initial

82 files changed, 40225 insertions, 0 deletions

diff --git a/include/jsoncons_ext/LICENSE b/include/jsoncons_ext/LICENSE
new file mode 100644
index 0000000..ecf46ab
--- /dev/null
+++ b/include/jsoncons_ext/LICENSE
@@ -0,0 +1,28 @@
+//          Copyright Daniel Parker 2013 - 2020.
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/include/jsoncons_ext/bson/bson.hpp b/include/jsoncons_ext/bson/bson.hpp
new file mode 100644
index 0000000..ec3192d
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson.hpp
@@ -0,0 +1,23 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_HPP
+#define JSONCONS_BSON_BSON_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/bson/bson_encoder.hpp>
+#include <jsoncons_ext/bson/bson_reader.hpp>
+#include <jsoncons_ext/bson/bson_cursor.hpp>
+#include <jsoncons_ext/bson/encode_bson.hpp>
+#include <jsoncons_ext/bson/decode_bson.hpp>
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_cursor.hpp b/include/jsoncons_ext/bson/bson_cursor.hpp
new file mode 100644
index 0000000..8baee53
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_cursor.hpp
@@ -0,0 +1,320 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_CURSOR_HPP
+#define JSONCONS_BSON_BSON_CURSOR_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/staj_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons_ext/bson/bson_parser.hpp>
+
+namespace jsoncons { 
+namespace bson {
+
+template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>>
+class basic_bson_cursor : public basic_staj_cursor<char>, private virtual ser_context
+{
+    using super_type = basic_staj_cursor<char>;
+public:
+    using source_type = Source;
+    using char_type = char;
+    using allocator_type = Allocator;
+private:
+    basic_bson_parser<Source,Allocator> parser_;
+    basic_staj_visitor<char_type> cursor_visitor_;
+    bool eof_;
+
+    // Noncopyable and nonmoveable
+    basic_bson_cursor(const basic_bson_cursor&) = delete;
+    basic_bson_cursor& operator=(const basic_bson_cursor&) = delete;
+
+public:
+    using string_view_type = string_view;
+
+    template <class Sourceable>
+    basic_bson_cursor(Sourceable&& source,
+                      const bson_decode_options& options = bson_decode_options(),
+                      const Allocator& alloc = Allocator())
+        : parser_(std::forward<Sourceable>(source), options, alloc), 
+          cursor_visitor_(accept_all),
+          eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    // Constructors that set parse error codes
+
+    template <class Sourceable>
+    basic_bson_cursor(Sourceable&& source,
+                      std::error_code& ec)
+        : basic_bson_cursor(std::allocator_arg, Allocator(),
+                            std::forward<Sourceable>(source), 
+                            bson_decode_options(), 
+                            ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_bson_cursor(Sourceable&& source,
+                      const bson_decode_options& options,
+                      std::error_code& ec)
+        : basic_bson_cursor(std::allocator_arg, Allocator(),
+                            std::forward<Sourceable>(source), 
+                            options, 
+                            ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_bson_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                      Sourceable&& source,
+                      const bson_decode_options& options,
+                      std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         cursor_visitor_(accept_all),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    void reset()
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    void reset(std::error_code& ec)
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source, std::error_code& ec)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    bool done() const override
+    {
+        return parser_.done();
+    }
+
+    void array_expected(std::error_code& ec) override
+    {
+        if (cursor_visitor_.event().event_type() == staj_event_type::begin_object)
+        {
+            parser_.array_expected(cursor_visitor_, ec);
+        }
+        else
+        { 
+            super_type::array_expected(ec);
+        }
+    }
+
+    const staj_event& current() const override
+    {
+        return cursor_visitor_.event();
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor) override
+    {
+        std::error_code ec;
+        read_to(visitor, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor,
+                std::error_code& ec) override
+    {
+        if (staj_to_saj_event(cursor_visitor_.event(), visitor, *this, ec))
+        {
+            read_next(visitor, ec);
+        }
+    }
+
+    void next() override
+    {
+        std::error_code ec;
+        next(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void next(std::error_code& ec) override
+    {
+        read_next(ec);
+    }
+
+    const ser_context& context() const override
+    {
+        return *this;
+    }
+
+    bool eof() const
+    {
+        return eof_;
+    }
+
+    std::size_t line() const override
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const override
+    {
+        return parser_.column();
+    }
+
+    friend
+    staj_filter_view operator|(basic_bson_cursor& cursor, 
+                               std::function<bool(const staj_event&, const ser_context&)> pred)
+    {
+        return staj_filter_view(cursor, pred);
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_bson_cursor(Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      std::error_code& ec)
+       : basic_bson_cursor(std::allocator_arg, Allocator(), 
+                           std::forward<Sourceable>(source), filter, ec)
+    {
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_bson_cursor(Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      const bson_decode_options& options = bson_decode_options(),
+                      const Allocator& alloc = Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(filter), 
+         eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_bson_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                      Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter, 
+                      std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source),alloc), 
+         cursor_visitor_(filter),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&)")
+    void read(basic_json_visitor<char_type>& visitor)
+    {
+        read_to(visitor);
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&, std::error_code&)")
+    void read(basic_json_visitor<char_type>& visitor,
+                 std::error_code& ec) 
+    {
+        read_to(visitor, ec);
+    }
+#endif
+private:
+    static bool accept_all(const staj_event&, const ser_context&) 
+    {
+        return true;
+    }
+
+    void read_next(std::error_code& ec)
+    {
+        parser_.restart();
+        while (!parser_.stopped())
+        {
+            parser_.parse(cursor_visitor_, ec);
+            if (ec) return;
+        }
+    }
+
+    void read_next(basic_json_visitor<char_type>& visitor, std::error_code& ec)
+    {
+        parser_.restart();
+        while (!parser_.stopped())
+        {
+            parser_.parse(visitor, ec);
+            if (ec) return;
+        }
+    }
+};
+
+using bson_stream_cursor = basic_bson_cursor<jsoncons::binary_stream_source>;
+using bson_bytes_cursor = basic_bson_cursor<jsoncons::bytes_source>;
+
+} // namespace bson
+} // namespace jsoncons
+
+#endif
+
diff --git a/include/jsoncons_ext/bson/bson_decimal128.hpp b/include/jsoncons_ext/bson/bson_decimal128.hpp
new file mode 100644
index 0000000..b487a04
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_decimal128.hpp
@@ -0,0 +1,865 @@
+#ifndef JSONCONS_BSON_BSON_DECIMAL128_HPP
+#define JSONCONS_BSON_BSON_DECIMAL128_HPP
+
+/*
+ *  Implements decimal128_to_chars and decimal128_from_chars
+ *  
+ *  Based on the libjson functions bson_decimal128_to_string
+ *  and bson_decimal128_from_string_w_len, available at
+ *  https://github.com/mongodb/mongo-c-driver/blob/master/src/libbson/src/bson/bson-decimal128.h
+ *  and https://github.com/mongodb/mongo-c-driver/blob/master/src/libbson/src/bson/bson-decimal128.c
+ *  
+*/
+
+/*
+ * Copyright 2015 MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <cstring>
+#include <ctype.h>
+#include <system_error>
+#include <algorithm>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace bson {
+
+    struct decimal128_to_chars_result 
+    {
+        char* ptr;
+        std::errc ec;
+    };
+
+    struct decimal128_from_chars_result 
+    {
+        const char* ptr;
+        std::errc ec;
+    };
+
+/**
+ * BSON_DECIMAL128_STRING:
+ *
+ * The length of a decimal128 string (with null terminator).
+ *
+ * 1  for the sign
+ * 35 for digits and radix
+ * 2  for exponent indicator and sign
+ * 4  for exponent digits
+ */
+#define BSON_DECIMAL128_STRING 43
+
+    struct TP1 
+    { 
+        uint64_t low; 
+        uint64_t high; 
+
+        constexpr TP1() : low(0), high(0) {}
+        constexpr TP1(uint64_t hi, uint64_t lo) : low(lo), high(hi) {}
+    };
+    struct TP2 
+    { 
+        uint64_t high; 
+        uint64_t low; 
+
+        constexpr TP2() : high(0), low(0) {}
+        constexpr TP2(uint64_t hi, uint64_t lo) : high(hi), low(lo) {}
+    };
+
+    typedef std::conditional<
+        jsoncons::endian::native == jsoncons::endian::little,
+        TP1,
+        TP2
+    >::type decimal128_t;
+
+    inline
+    bool operator==(const decimal128_t& lhs, const decimal128_t& rhs)
+    {
+       return lhs.high == rhs.high && lhs.low == rhs.low;
+    }   
+
+    inline
+    bool operator!=(const decimal128_t& lhs, const decimal128_t& rhs)
+    {
+       return !(lhs == rhs);
+    }   
+
+    struct decimal128_limits
+    {
+        // The length of a decimal128 string (without null terminator).
+        //
+        // 1  for the sign
+        // 35 for digits and radix
+        // 2  for exponent indicator and sign
+        // 4  for exponent digits
+        static constexpr int buf_size = 42;  
+        static constexpr int exponent_max = 6111;
+        static constexpr int exponent_min = -6176;
+        static constexpr int exponent_bias = 6176;
+        static constexpr int max_digits = 34;
+
+        static constexpr decimal128_t nan() {return decimal128_t(0x7c00000000000000ull, 0);}
+        static constexpr decimal128_t infinity() {return decimal128_t(0x7800000000000000ull, 0);}
+        static constexpr decimal128_t neg_infinity() {return decimal128_t(0x7800000000000000ull + 0x8000000000000000ull, 0);}
+    };
+
+    inline
+    bool is_nan(decimal128_t dec) { return dec == decimal128_limits::nan(); }
+
+    inline
+    bool is_inf(decimal128_t dec) { return dec == decimal128_limits::infinity(); }
+
+    inline
+    bool is_neg_inf(decimal128_t dec) { return dec == decimal128_limits::neg_infinity(); }
+
+    /**
+     * bson_uint128_t:
+     *
+     * This struct represents a 128 bit integer.
+     */
+    typedef struct {
+       uint32_t parts[4]; /* 32-bit words stored high to low. */
+    } bson_uint128_t;
+
+    typedef struct {
+       uint64_t high, low;
+    } bson_uint128_6464_t;
+
+    namespace detail {
+    
+        /**
+         *------------------------------------------------------------------------------
+         *
+         * bson_uint128_divide1B --
+         *
+         *    This function divides a #bson_uint128_t by 1000000000 (1 billion) and
+         *    computes the quotient and remainder.
+         *
+         *    The remainder will contain 9 decimal digits for conversion to string.
+         *
+         * @value     The #bson_uint128_t operand.
+         * @quotient  A pointer to store the #bson_uint128_t quotient.
+         * @rem       A pointer to store the #uint64_t remainder.
+         *
+         * Returns:
+         *    The quotient at @quotient and the remainder at @rem.
+         *
+         * Side effects:
+         *    None.
+         *
+         *------------------------------------------------------------------------------
+         */
+
+        inline
+        void bson_uint128_divide1B (bson_uint128_t value,     /* IN */
+                                     bson_uint128_t *quotient, /* OUT */
+                                     uint32_t *rem)             /* OUT */
+        {
+            const uint32_t DIVISOR = 1000 * 1000 * 1000;
+            uint64_t _rem = 0;
+            int i = 0;
+            
+            if (!value.parts[0] && !value.parts[1] && !value.parts[2] &&
+                !value.parts[3]) {
+               *quotient = value;
+               *rem = 0;
+               return;
+            }
+            
+            for (i = 0; i <= 3; i++) {
+               _rem <<= 32; /* Adjust remainder to match value of next dividend */
+               _rem += value.parts[i]; /* Add the divided to _rem */
+               value.parts[i] = (uint32_t) (_rem / DIVISOR);
+               _rem %= DIVISOR; /* Store the remainder */
+            }
+            
+            *quotient = value;
+            *rem = (uint32_t) _rem;
+        }
+
+        /**
+         *-------------------------------------------------------------------------
+         *
+         * mul64x64 --
+         *
+         *    This function multiplies two &uint64_t into a &bson_uint128_6464_t.
+         *
+         * Returns:
+         *    The product of @left and @right.
+         *
+         * Side Effects:
+         *    None.
+         *
+         *-------------------------------------------------------------------------
+         */
+
+        inline
+        void mul_64x64 (uint64_t left,                 /* IN */
+                        uint64_t right,                /* IN */
+                        bson_uint128_6464_t *product) /* OUT */
+        {
+            uint64_t left_high, left_low, right_high, right_low, product_high,
+               product_mid, product_mid2, product_low;
+            bson_uint128_6464_t rt = {0,0};
+ 
+            if (!left && !right) {
+               *product = rt;
+               return;
+            }
+ 
+            left_high = left >> 32;
+            left_low = (uint32_t) left;
+            right_high = right >> 32;
+            right_low = (uint32_t) right;
+ 
+            product_high = left_high * right_high;
+            product_mid = left_high * right_low;
+            product_mid2 = left_low * right_high;
+            product_low = left_low * right_low;
+ 
+            product_high += product_mid >> 32;
+            product_mid = (uint32_t) product_mid + product_mid2 + (product_low >> 32);
+ 
+            product_high = product_high + (product_mid >> 32);
+            product_low = (product_mid << 32) + (uint32_t) product_low;
+ 
+            rt.high = product_high;
+            rt.low = product_low;
+            *product = rt;
+        }
+
+        /**
+         *------------------------------------------------------------------------------
+         *
+         * dec128_tolower --
+         *
+         *    This function converts the ASCII character @c to lowercase.  It is locale
+         *    insensitive (unlike the stdlib tolower).
+         *
+         * Returns:
+         *    The lowercased character.
+         */
+
+        inline
+        char dec128_tolower (char c)
+        {
+           if (isupper (c)) {
+              c += 32;
+           }
+
+           return c;
+        }
+
+        /**
+         *------------------------------------------------------------------------------
+         *
+         * dec128_istreq --
+         *
+         *    This function compares the null-terminated *ASCII* strings @a and @b
+         *    for case-insensitive equality.
+         *
+         * Returns:
+         *    true if the strings are equal, false otherwise.
+         */
+
+        inline
+        bool dec128_istreq (const char* a, const char* lasta,
+                            const char* b, const char* lastb)
+        {
+            while (!(a == lasta && b == lastb)) 
+            {
+               // strings are different lengths
+               if (a == lasta || b == lastb) 
+               {
+                  return false;
+               }
+         
+               if (dec128_tolower (*a) != dec128_tolower (*b)) {
+                  return false;
+               }
+         
+               a++;
+               b++;
+            }
+         
+            return true;
+        }
+
+    } // namespace detail
+
+
+    /**
+     *------------------------------------------------------------------------------
+     *
+     * decimal128_to_chars --
+     *
+     *    This function converts a BID formatted decimal128 value to string,
+     *    accepting a &decimal128_t as @dec.  The string is stored at @str.
+     *
+     * @dec : The BID formatted decimal to convert.
+     * @str : The output decimal128 string. At least %BSON_DECIMAL128_STRING
+     *characters.
+     *
+     * Returns:
+     *    None.
+     *
+     * Side effects:
+     *    None.
+     *
+     *------------------------------------------------------------------------------
+     */
+
+    inline
+    decimal128_to_chars_result decimal128_to_chars(char* first, char* last, const decimal128_t& dec)
+    {
+        const std::string bson_decimal128_inf = "Infinity";
+        const std::string bson_decimal128_nan = "NaN";
+
+        const uint32_t combination_mask = 0x1f;   /* Extract least significant 5 bits */
+        const uint32_t exponent_mask = 0x3fff;    /* Extract least significant 14 bits */
+        const uint32_t combination_infinity = 30; /* Value of combination field for Inf */
+        const uint32_t combination_nan = 31;      /* Value of combination field for NaN */
+        const uint32_t exponent_bias = 6176;      /* decimal128 exponent bias */
+
+        char* str_out = first;      /* output pointer in string */
+        char significand_str[35]; /* decoded significand digits */
+
+        /* Note: bits in this routine are referred to starting at 0, */
+        /* from the sign bit, towards the coefficient. */
+        uint32_t high;                   /* bits 0 - 31 */
+        uint32_t midh;                   /* bits 32 - 63 */
+        uint32_t midl;                   /* bits 64 - 95 */
+        uint32_t low;                    /* bits 96 - 127 */
+        uint32_t combination;            /* bits 1 - 5 */
+        uint32_t biased_exponent;        /* decoded biased exponent (14 bits) */
+        uint32_t significand_digits = 0; /* the number of significand digits */
+        uint32_t significand[36] = {0};  /* the base-10 digits in the significand */
+        uint32_t *significand_read = significand; /* read pointer into significand */
+        int32_t exponent;                         /* unbiased exponent */
+        int32_t scientific_exponent; /* the exponent if scientific notation is
+                                      * used */
+        bool is_zero = false;        /* true if the number is zero */
+ 
+        uint8_t significand_msb; /* the most signifcant significand bits (50-46) */
+        bson_uint128_t
+           significand128; /* temporary storage for significand decoding */
+ 
+        memset (significand_str, 0, sizeof (significand_str));
+ 
+        if ((int64_t) dec.high < 0) { /* negative */
+           *(str_out++) = '-';
+        }
+ 
+        low = (uint32_t) dec.low, midl = (uint32_t) (dec.low >> 32),
+        midh = (uint32_t) dec.high, high = (uint32_t) (dec.high >> 32);
+ 
+        /* Decode combination field and exponent */
+        combination = (high >> 26) & combination_mask;
+ 
+        if (JSONCONS_UNLIKELY ((combination >> 3) == 3)) {
+           /* Check for 'special' values */
+           if (combination == combination_infinity) { /* Infinity */
+               if (last-str_out >= static_cast<ptrdiff_t >(bson_decimal128_inf.size())) 
+               {
+                   std::memcpy(str_out, bson_decimal128_inf.data(), bson_decimal128_inf.size());
+                   str_out += bson_decimal128_inf.size();
+               }
+               *str_out = 0;
+              //strcpy_s (str_out, last-str_out, bson_decimal128_inf.c_str());
+              return decimal128_to_chars_result{str_out, std::errc()};
+           } else if (combination == combination_nan) { /* NaN */
+               /* first, not str_out, to erase the sign */
+               str_out = first;
+               if (last-str_out >= static_cast<ptrdiff_t >(bson_decimal128_nan.size())) 
+               {
+                   std::memcpy(str_out, bson_decimal128_nan.data(), bson_decimal128_nan.size());
+                   str_out += bson_decimal128_nan.size();
+               }
+               *str_out = 0;
+              //strcpy_s (first, last-first, bson_decimal128_nan.c_str());
+              /* we don't care about the NaN payload. */
+               return decimal128_to_chars_result{str_out, std::errc()};
+           } else {
+              biased_exponent = (high >> 15) & exponent_mask;
+              significand_msb = 0x8 + ((high >> 14) & 0x1);
+           }
+        } else {
+           significand_msb = (high >> 14) & 0x7;
+           biased_exponent = (high >> 17) & exponent_mask;
+        }
+ 
+        exponent = biased_exponent - exponent_bias;
+        /* Create string of significand digits */
+ 
+        /* Convert the 114-bit binary number represented by */
+        /* (high, midh, midl, low) to at most 34 decimal */
+        /* digits through modulo and division. */
+        significand128.parts[0] = (high & 0x3fff) + ((significand_msb & 0xf) << 14);
+        significand128.parts[1] = midh;
+        significand128.parts[2] = midl;
+        significand128.parts[3] = low;
+ 
+        if (significand128.parts[0] == 0 && significand128.parts[1] == 0 &&
+            significand128.parts[2] == 0 && significand128.parts[3] == 0) {
+           is_zero = true;
+        } else if (significand128.parts[0] >= (1 << 17)) {
+           /* The significand is non-canonical or zero.
+            * In order to preserve compatibility with the densely packed decimal
+            * format, the maximum value for the significand of decimal128 is
+            * 1e34 - 1.  If the value is greater than 1e34 - 1, the IEEE 754
+            * standard dictates that the significand is interpreted as zero.
+            */
+           is_zero = true;
+        } else {
+           for (int k = 3; k >= 0; k--) {
+              uint32_t least_digits = 0;
+              detail::bson_uint128_divide1B (
+                 significand128, &significand128, &least_digits);
+ 
+              /* We now have the 9 least significant digits (in base 2). */
+              /* Convert and output to string. */
+              if (!least_digits) {
+                 continue;
+              }
+ 
+              for (int j = 8; j >= 0; j--) {
+                 significand[k * 9 + j] = least_digits % 10;
+                 least_digits /= 10;
+              }
+           }
+        }
+ 
+        /* Output format options: */
+        /* Scientific - [-]d.dddE(+/-)dd or [-]dE(+/-)dd */
+        /* Regular    - ddd.ddd */
+ 
+        if (is_zero) {
+           significand_digits = 1;
+           *significand_read = 0;
+        } else {
+           significand_digits = 36;
+           while (!(*significand_read)) {
+              significand_digits--;
+              significand_read++;
+           }
+        }
+ 
+        scientific_exponent = significand_digits - 1 + exponent;
+ 
+        /* The scientific exponent checks are dictated by the string conversion
+         * specification and are somewhat arbitrary cutoffs.
+         *
+         * We must check exponent > 0, because if this is the case, the number
+         * has trailing zeros.  However, we *cannot* output these trailing zeros,
+         * because doing so would change the precision of the value, and would
+         * change stored data if the string converted number is round tripped.
+         */
+        if (scientific_exponent < -6 || exponent > 0) {
+           /* Scientific format */
+           *(str_out++) = char(*(significand_read++)) + '0';
+           significand_digits--;
+ 
+           if (significand_digits) {
+              *(str_out++) = '.';
+           }
+ 
+           for (std::size_t i = 0; i < significand_digits && (str_out - first) < 36; i++) {
+              *(str_out++) = char(*(significand_read++)) + '0';
+           }
+           /* Exponent */
+           *(str_out++) = 'E';
+
+           std::string s;
+           if (scientific_exponent >= 0) {
+               s.push_back('+');
+           }
+           jsoncons::detail::from_integer(scientific_exponent, s);
+           if (str_out + s.size() < last) 
+           {
+               std::memcpy(str_out, s.data(), s.size());
+           }
+           else
+           {
+               return decimal128_to_chars_result{str_out, std::errc::value_too_large};
+           }
+           str_out += s.size();
+        } else {
+           /* Regular format with no decimal place */
+           if (exponent >= 0) {
+              for (std::size_t i = 0; i < significand_digits && (str_out - first) < 36; i++) {
+                 *(str_out++) = char(*(significand_read++)) + '0';
+              }
+           } else {
+              int32_t radix_position = significand_digits + exponent;
+ 
+              if (radix_position > 0) { /* non-zero digits before radix */
+                 for (int32_t i = 0;
+                      i < radix_position && (str_out < last);
+                      i++) {
+                    *(str_out++) = char(*(significand_read++)) + '0';
+                 }
+              } else { /* leading zero before radix point */
+                 *(str_out++) = '0';
+              }
+ 
+              *(str_out++) = '.';
+              while (radix_position++ < 0) { /* add leading zeros after radix */
+                 *(str_out++) = '0';
+              }
+ 
+              for (std::size_t i = 0;
+                   (i < significand_digits - (std::max) (radix_position - 1, 0)) &&
+                   (str_out < last);
+                   i++) {
+                 *(str_out++) = char(*(significand_read++)) + '0';
+              }
+           }
+        }
+        return decimal128_to_chars_result{str_out, std::errc()};
+    }
+
+
+
+    /**
+     *------------------------------------------------------------------------------
+     *
+     * bson_decimal128_from_string_w_len --
+     *
+     *    This function converts @string in the format [+-]ddd[.]ddd[E][+-]dddd to
+     *    decimal128.  Out of range values are converted to +/-Infinity.  Invalid
+     *    strings are converted to NaN. @len is the length of the string, or -1
+     *    meaning the string is null-terminated.
+     *
+     *    If more digits are provided than the available precision allows,
+     *    round to the nearest expressable decimal128 with ties going to even will
+     *    occur.
+     *
+     *    Note: @string must be ASCII only!
+     *
+     * Returns:
+     *    true on success, or false on failure. @dec will be NaN if @str was invalid
+     *    The &decimal128_t converted from @string at @dec.
+     *
+     * Side effects:
+     *    None.
+     *
+     *------------------------------------------------------------------------------
+     */
+
+    inline
+    decimal128_from_chars_result decimal128_from_chars(const char* first, const char* last, decimal128_t& dec) 
+    {
+        const string_view inf_str = "inf";
+        const string_view infinity_str = "infinity";
+        const string_view nan_str = "nan";
+
+        ptrdiff_t len = last - first;
+
+        bson_uint128_6464_t significand = {0,0};
+ 
+        const char* str_read = first; /* Read pointer for consuming str. */
+ 
+        /* Parsing state tracking */
+        bool is_negative = false;
+        bool saw_radix = false;
+        bool includes_sign = false; /* True if the input first contains a sign. */
+        bool found_nonzero = false;
+ 
+        size_t significant_digits = 0; /* Total number of significant digits
+                                        * (no leading or trailing zero) */
+        size_t ndigits_read = 0;       /* Total number of significand digits read */
+        size_t ndigits = 0;        /* Total number of digits (no leading zeros) */
+        size_t radix_position = 0; /* The number of the digits after radix */
+        size_t first_nonzero = 0;  /* The index of the first non-zero in *str* */
+ 
+        uint16_t digits[decimal128_limits::max_digits] = {0};
+        uint16_t ndigits_stored = 0;      /* The number of digits in digits */
+        uint16_t *digits_insert = digits; /* Insertion pointer for digits */
+        size_t first_digit = 0;           /* The index of the first non-zero digit */
+        size_t last_digit = 0;            /* The index of the last digit */
+ 
+        int32_t exponent = 0;
+        uint64_t significand_high = 0; /* The high 17 digits of the significand */
+        uint64_t significand_low = 0;  /* The low 17 digits of the significand */
+        uint16_t biased_exponent = 0;  /* The biased exponent */
+ 
+        dec.high = 0;
+        dec.low = 0;
+ 
+        if (*str_read == '+' || *str_read == '-') {
+           is_negative = *(str_read++) == '-';
+           includes_sign = true;
+        }
+
+        /* Check for Infinity or NaN */
+        if (!isdigit (*str_read) && *str_read != '.') {
+           if (detail::dec128_istreq (str_read, last, inf_str.data(), inf_str.data()+inf_str.length()) ||
+               detail::dec128_istreq (str_read, last, infinity_str.data(), infinity_str.data()+infinity_str.length())) 
+           {
+               dec = is_negative ? decimal128_limits::neg_infinity() : decimal128_limits::infinity();
+              return decimal128_from_chars_result{str_read,std::errc()};
+           } else if (detail::dec128_istreq (str_read, last, nan_str.data(), nan_str.data()+nan_str.length())) {
+              dec = decimal128_limits::nan();
+              return decimal128_from_chars_result{str_read,std::errc()};
+           }
+ 
+           dec = decimal128_limits::nan();
+           return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+        }
+ 
+        /* Read digits */
+        while (((isdigit (*str_read) || *str_read == '.')) &&
+               (len == -1 || str_read < first + len)) {
+           if (*str_read == '.') {
+              if (saw_radix) {
+                 dec = decimal128_limits::nan();
+                 return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+              }
+ 
+              saw_radix = true;
+              str_read++;
+              continue;
+           }
+ 
+           if (ndigits_stored < 34) {
+              if (*str_read != '0' || found_nonzero) {
+                 if (!found_nonzero) {
+                    first_nonzero = ndigits_read;
+                 }
+ 
+                 found_nonzero = true;
+                 *(digits_insert++) = *(str_read) - '0'; /* Only store 34 digits */
+                 ndigits_stored++;
+              }
+           }
+ 
+           if (found_nonzero) {
+              ndigits++;
+           }
+ 
+           if (saw_radix) {
+              radix_position++;
+           }
+ 
+           ndigits_read++;
+           str_read++;
+        }
+ 
+        if (saw_radix && !ndigits_read) {
+           dec = decimal128_limits::nan();
+           return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+        }
+ 
+        /* Read exponent if exists */
+        if (*str_read == 'e' || *str_read == 'E') {
+           ++str_read;
+           if (*str_read == '+') {
+               ++str_read;
+           }
+           auto result = jsoncons::detail::to_integer(str_read, last - str_read, exponent);
+           if (result.ec != jsoncons::detail::to_integer_errc()) 
+           {
+               dec = decimal128_limits::nan();
+               return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+           }
+           str_read = result.ptr;
+        }
+
+        if ((len == -1 || str_read < first + len) && *str_read) {
+           dec = decimal128_limits::nan();
+           return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+        }
+ 
+        /* Done reading input. */
+        /* Find first non-zero digit in digits */
+        first_digit = 0;
+ 
+        if (!ndigits_stored) { /* value is zero */
+           first_digit = 0;
+           last_digit = 0;
+           digits[0] = 0;
+           ndigits = 1;
+           ndigits_stored = 1;
+           significant_digits = 0;
+        } else {
+           last_digit = ndigits_stored - 1;
+           significant_digits = ndigits;
+           /* Mark trailing zeros as non-significant */
+           while (first[first_nonzero + significant_digits - 1 + includes_sign +
+                         saw_radix] == '0') {
+              significant_digits--;
+           }
+        }
+ 
+ 
+        /* Normalization of exponent */
+        /* Correct exponent based on radix position, and shift significand as needed
+         */
+        /* to represent user input */
+ 
+        /* Overflow prevention */
+        if (exponent <= static_cast<int32_t>(radix_position) && static_cast<int32_t>(radix_position) - exponent > (1 << 14)) {
+           exponent = decimal128_limits::exponent_min;
+        } else {
+           exponent -= static_cast<int32_t>(radix_position);
+        }
+ 
+        /* Attempt to normalize the exponent */
+        while (exponent > decimal128_limits::exponent_max) {
+           /* Shift exponent to significand and decrease */
+           last_digit++;
+ 
+           if (last_digit - first_digit > decimal128_limits::max_digits) {
+              /* The exponent is too great to shift into the significand. */
+              if (significant_digits == 0) {
+                 /* Value is zero, we are allowed to clamp the exponent. */
+                 exponent = decimal128_limits::exponent_max;
+                 break;
+              }
+ 
+              /* Overflow is not permitted, error. */
+              dec = decimal128_limits::nan();
+              return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+           }
+ 
+           exponent--;
+        }
+ 
+        while (exponent < decimal128_limits::exponent_min || ndigits_stored < ndigits) {
+           /* Shift last digit */
+           if (last_digit == 0) {
+              /* underflow is not allowed, but zero clamping is */
+              if (significant_digits == 0) {
+                 exponent = decimal128_limits::exponent_min;
+                 break;
+              }
+ 
+              dec = decimal128_limits::nan();
+              return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+           }
+ 
+           if (ndigits_stored < ndigits) {
+              if (first[ndigits - 1 + includes_sign + saw_radix] - '0' != 0 &&
+                  significant_digits != 0) {
+                 dec = decimal128_limits::nan();
+                 return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+              }
+ 
+              ndigits--; /* adjust to match digits not stored */
+           } else {
+              if (digits[last_digit] != 0) {
+                 /* Inexact rounding is not allowed. */
+                 dec = decimal128_limits::nan();
+                 return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+              }
+ 
+ 
+              last_digit--; /* adjust to round */
+           }
+ 
+           if (exponent < decimal128_limits::exponent_max) {
+              exponent++;
+           } else {
+              dec = decimal128_limits::nan();
+              return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+           }
+        }
+ 
+        /* Round */
+        /* We've normalized the exponent, but might still need to round. */
+        if (last_digit - first_digit + 1 < significant_digits) {
+           uint8_t round_digit;
+ 
+           /* There are non-zero digits after last_digit that need rounding. */
+           /* We round to nearest, ties to even */
+           round_digit =
+              first[first_nonzero + last_digit + includes_sign + saw_radix + 1] -
+              '0';
+ 
+           if (round_digit != 0) {
+              /* Inexact (non-zero) rounding is not allowed */
+              dec = decimal128_limits::nan();
+              return decimal128_from_chars_result{str_read,std::errc::invalid_argument};
+           }
+        }
+ 
+        /* Encode significand */
+        significand_high = 0,   /* The high 17 digits of the significand */
+           significand_low = 0; /* The low 17 digits of the significand */
+ 
+        if (significant_digits == 0) { /* read a zero */
+           significand_high = 0;
+           significand_low = 0;
+        } else if (last_digit - first_digit < 17) {
+           size_t d_idx = first_digit;
+           significand_low = digits[d_idx++];
+ 
+           for (; d_idx <= last_digit; d_idx++) {
+              significand_low *= 10;
+              significand_low += digits[d_idx];
+              significand_high = 0;
+           }
+        } else {
+           size_t d_idx = first_digit;
+           significand_high = digits[d_idx++];
+ 
+           for (; d_idx <= last_digit - 17; d_idx++) {
+              significand_high *= 10;
+              significand_high += digits[d_idx];
+           }
+ 
+           significand_low = digits[d_idx++];
+ 
+           for (; d_idx <= last_digit; d_idx++) {
+              significand_low *= 10;
+              significand_low += digits[d_idx];
+           }
+        }
+ 
+        detail::mul_64x64 (significand_high, 100000000000000000ull, &significand);
+        significand.low += significand_low;
+ 
+        if (significand.low < significand_low) {
+           significand.high += 1;
+        }
+ 
+ 
+        biased_exponent = static_cast<uint16_t>(exponent + static_cast<int32_t>(decimal128_limits::exponent_bias));
+ 
+        /* Encode combination, exponent, and significand. */
+        if ((significand.high >> 49) & 1) {
+           /* Encode '11' into bits 1 to 3 */
+           dec.high |= (0x3ull << 61);
+           dec.high |= (biased_exponent & 0x3fffull) << 47;
+           dec.high |= significand.high & 0x7fffffffffffull;
+        } else {
+           dec.high |= (biased_exponent & 0x3fffull) << 49;
+           dec.high |= significand.high & 0x1ffffffffffffull;
+        }
+ 
+        dec.low = significand.low;
+ 
+        /* Encode sign */
+        if (is_negative) {
+           dec.high |= 0x8000000000000000ull;
+        }
+ 
+        return decimal128_from_chars_result{str_read,std::errc()};
+    }
+
+} // namespace bson
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_decimal128.hpp.bak b/include/jsoncons_ext/bson/bson_decimal128.hpp.bak
new file mode 100644
index 0000000..8e27ee1
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_decimal128.hpp.bak
@@ -0,0 +1,816 @@
+#ifndef JSONCONS_BSON_BSON_DECIMAL128_HPP
+#define JSONCONS_BSON_BSON_DECIMAL128_HPP
+
+/*
+ * Copyright 2015 MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <system_error>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace bson {
+
+    struct decimal128_to_chars_result 
+    {
+        char* ptr;
+        std::errc ec;
+    };
+
+    struct decimal128_from_chars_result 
+    {
+        const char* ptr;
+        std::errc ec;
+    };
+
+/**
+ * BSON_DECIMAL128_STRING:
+ *
+ * The length of a decimal128 string (with null terminator).
+ *
+ * 1  for the sign
+ * 35 for digits and radix
+ * 2  for exponent indicator and sign
+ * 4  for exponent digits
+ */
+#define BSON_DECIMAL128_STRING 43
+#define BSON_DECIMAL128_INF "Infinity"
+#define BSON_DECIMAL128_NAN "NaN"
+
+    struct TP1 
+    { 
+        uint64_t low; 
+        uint64_t high; 
+
+        constexpr TP1() : low(0), high(0) {}
+        constexpr TP1(uint64_t hi, uint64_t lo) : low(lo), high(hi) {}
+    };
+    struct TP2 
+    { 
+        uint64_t high; 
+        uint64_t low; 
+
+        constexpr TP2() : high(0), low(0) {}
+        constexpr TP2(uint64_t hi, uint64_t lo) : high(hi), low(lo) {}
+    };
+
+    typedef typename std::conditional<
+        jsoncons::endian::native == jsoncons::endian::little,
+        TP1,
+        TP2
+    >::type decimal128_t;
+
+    inline
+    bool operator==(const decimal128_t& lhs, const decimal128_t& rhs)
+    {
+       return lhs.high == rhs.high && lhs.low == rhs.low;
+    }   
+
+    inline
+    bool operator!=(const decimal128_t& lhs, const decimal128_t& rhs)
+    {
+       return !(lhs == rhs);
+    }   
+
+    struct decimal128_limits
+    {
+        // The length of a decimal128 string (without null terminator).
+        //
+        // 1  for the sign
+        // 35 for digits and radix
+        // 2  for exponent indicator and sign
+        // 4  for exponent digits
+        static constexpr int recommended_buffer_size = 42;  
+        static constexpr decimal128_t nan = decimal128_t(0x7c00000000000000ull, 0);
+        static constexpr decimal128_t infinity = decimal128_t(0x7800000000000000ull, 0);
+        static constexpr decimal128_t neg_infinity = decimal128_t(0x7800000000000000ull + 0x8000000000000000ull, 0);
+        static constexpr int exponent_max = 6111;
+        static constexpr int exponent_min = -6176;
+        static constexpr int exponent_bias = 6176;
+        static constexpr int max_digits = 34;
+    };
+
+    /**
+     * bson_uint128_t:
+     *
+     * This struct represents a 128 bit integer.
+     */
+    typedef struct {
+       uint32_t parts[4]; /* 32-bit words stored high to low. */
+    } bson_uint128_t;
+
+    typedef struct {
+       uint64_t high, low;
+    } bson_uint128_6464_t;
+
+    namespace detail {
+    
+        /**
+         *------------------------------------------------------------------------------
+         *
+         * bson_uint128_divide1B --
+         *
+         *    This function divides a #bson_uint128_t by 1000000000 (1 billion) and
+         *    computes the quotient and remainder.
+         *
+         *    The remainder will contain 9 decimal digits for conversion to string.
+         *
+         * @value     The #bson_uint128_t operand.
+         * @quotient  A pointer to store the #bson_uint128_t quotient.
+         * @rem       A pointer to store the #uint64_t remainder.
+         *
+         * Returns:
+         *    The quotient at @quotient and the remainder at @rem.
+         *
+         * Side effects:
+         *    None.
+         *
+         *------------------------------------------------------------------------------
+         */
+
+        inline
+        void bson_uint128_divide1B (bson_uint128_t value,     /* IN */
+                                     bson_uint128_t *quotient, /* OUT */
+                                     uint32_t *rem)             /* OUT */
+        {
+           const uint32_t DIVISOR = 1000 * 1000 * 1000;
+           uint64_t _rem = 0;
+           int i = 0;
+
+           if (!value.parts[0] && !value.parts[1] && !value.parts[2] &&
+               !value.parts[3]) {
+              *quotient = value;
+              *rem = 0;
+              return;
+           }
+
+           for (i = 0; i <= 3; i++) {
+              _rem <<= 32; /* Adjust remainder to match value of next dividend */
+              _rem += value.parts[i]; /* Add the divided to _rem */
+              value.parts[i] = (uint32_t) (_rem / DIVISOR);
+              _rem %= DIVISOR; /* Store the remainder */
+           }
+
+           *quotient = value;
+           *rem = (uint32_t) _rem;
+        }
+
+        /**
+         *-------------------------------------------------------------------------
+         *
+         * mul64x64 --
+         *
+         *    This function multiplies two &uint64_t into a &bson_uint128_6464_t.
+         *
+         * Returns:
+         *    The product of @left and @right.
+         *
+         * Side Effects:
+         *    None.
+         *
+         *-------------------------------------------------------------------------
+         */
+
+        inline
+        void mul_64x64 (uint64_t left,                 /* IN */
+                        uint64_t right,                /* IN */
+                        bson_uint128_6464_t *product) /* OUT */
+        {
+           uint64_t left_high, left_low, right_high, right_low, product_high,
+              product_mid, product_mid2, product_low;
+           bson_uint128_6464_t rt = {0};
+
+           if (!left && !right) {
+              *product = rt;
+              return;
+           }
+
+           left_high = left >> 32;
+           left_low = (uint32_t) left;
+           right_high = right >> 32;
+           right_low = (uint32_t) right;
+
+           product_high = left_high * right_high;
+           product_mid = left_high * right_low;
+           product_mid2 = left_low * right_high;
+           product_low = left_low * right_low;
+
+           product_high += product_mid >> 32;
+           product_mid = (uint32_t) product_mid + product_mid2 + (product_low >> 32);
+
+           product_high = product_high + (product_mid >> 32);
+           product_low = (product_mid << 32) + (uint32_t) product_low;
+
+           rt.high = product_high;
+           rt.low = product_low;
+           *product = rt;
+        }
+
+        /**
+         *------------------------------------------------------------------------------
+         *
+         * dec128_tolower --
+         *
+         *    This function converts the ASCII character @c to lowercase.  It is locale
+         *    insensitive (unlike the stdlib tolower).
+         *
+         * Returns:
+         *    The lowercased character.
+         */
+
+        inline
+        char dec128_tolower (char c)
+        {
+           if (isupper (c)) {
+              c += 32;
+           }
+
+           return c;
+        }
+
+        /**
+         *------------------------------------------------------------------------------
+         *
+         * dec128_istreq --
+         *
+         *    This function compares the null-terminated *ASCII* strings @a and @b
+         *    for case-insensitive equality.
+         *
+         * Returns:
+         *    true if the strings are equal, false otherwise.
+         */
+
+        inline
+        bool dec128_istreq (const char* a, /* IN */
+                        const char* b /* IN */)
+        {
+           while (*a != '\0' || *b != '\0') {
+              /* strings are different lengths. */
+              if (*a == '\0' || *b == '\0') {
+                 return false;
+              }
+
+              if (dec128_tolower (*a) != dec128_tolower (*b)) {
+                 return false;
+              }
+
+              a++;
+              b++;
+           }
+
+           return true;
+        }
+
+    } // namespace detail
+
+
+    /**
+     *------------------------------------------------------------------------------
+     *
+     * decimal128_to_chars --
+     *
+     *    This function converts a BID formatted decimal128 value to string,
+     *    accepting a &decimal128_t as @dec.  The string is stored at @str.
+     *
+     * @dec : The BID formatted decimal to convert.
+     * @str : The output decimal128 string. At least %BSON_DECIMAL128_STRING
+     *characters.
+     *
+     * Returns:
+     *    None.
+     *
+     * Side effects:
+     *    None.
+     *
+     *------------------------------------------------------------------------------
+     */
+
+    inline
+    void decimal128_to_chars(char* first, char* last, const decimal128_t& dec)
+    {
+       uint32_t COMBINATION_MASK = 0x1f;   /* Extract least significant 5 bits */
+       uint32_t EXPONENT_MASK = 0x3fff;    /* Extract least significant 14 bits */
+       uint32_t COMBINATION_INFINITY = 30; /* Value of combination field for Inf */
+       uint32_t COMBINATION_NAN = 31;      /* Value of combination field for NaN */
+       uint32_t EXPONENT_BIAS = 6176;      /* decimal128 exponent bias */
+
+       char* str_out = first;      /* output pointer in string */
+       char significand_str[35]; /* decoded significand digits */
+
+
+       /* Note: bits in this routine are referred to starting at 0, */
+       /* from the sign bit, towards the coefficient. */
+       uint32_t high;                   /* bits 0 - 31 */
+       uint32_t midh;                   /* bits 32 - 63 */
+       uint32_t midl;                   /* bits 64 - 95 */
+       uint32_t low;                    /* bits 96 - 127 */
+       uint32_t combination;            /* bits 1 - 5 */
+       uint32_t biased_exponent;        /* decoded biased exponent (14 bits) */
+       uint32_t significand_digits = 0; /* the number of significand digits */
+       uint32_t significand[36] = {0};  /* the base-10 digits in the significand */
+       uint32_t *significand_read = significand; /* read pointer into significand */
+       int32_t exponent;                         /* unbiased exponent */
+       int32_t scientific_exponent; /* the exponent if scientific notation is
+                                     * used */
+       bool is_zero = false;        /* true if the number is zero */
+
+       uint8_t significand_msb; /* the most signifcant significand bits (50-46) */
+       bson_uint128_t
+          significand128; /* temporary storage for significand decoding */
+       size_t i;          /* indexing variables */
+       int j, k;
+
+       memset (significand_str, 0, sizeof (significand_str));
+
+       if ((int64_t) dec.high < 0) { /* negative */
+          *(str_out++) = '-';
+       }
+
+       low = (uint32_t) dec.low, midl = (uint32_t) (dec.low >> 32),
+       midh = (uint32_t) dec.high, high = (uint32_t) (dec.high >> 32);
+
+       /* Decode combination field and exponent */
+       combination = (high >> 26) & COMBINATION_MASK;
+
+       if (JSONCONS_UNLIKELY ((combination >> 3) == 3)) {
+          /* Check for 'special' values */
+          if (combination == COMBINATION_INFINITY) { /* Infinity */
+             strcpy (str_out, BSON_DECIMAL128_INF);
+             return;
+          } else if (combination == COMBINATION_NAN) { /* NaN */
+             /* first, not str_out, to erase the sign */
+             strcpy (first, BSON_DECIMAL128_NAN);
+             /* we don't care about the NaN payload. */
+             return;
+          } else {
+             biased_exponent = (high >> 15) & EXPONENT_MASK;
+             significand_msb = 0x8 + ((high >> 14) & 0x1);
+          }
+       } else {
+          significand_msb = (high >> 14) & 0x7;
+          biased_exponent = (high >> 17) & EXPONENT_MASK;
+       }
+
+       exponent = biased_exponent - EXPONENT_BIAS;
+       /* Create string of significand digits */
+
+       /* Convert the 114-bit binary number represented by */
+       /* (high, midh, midl, low) to at most 34 decimal */
+       /* digits through modulo and division. */
+       significand128.parts[0] = (high & 0x3fff) + ((significand_msb & 0xf) << 14);
+       significand128.parts[1] = midh;
+       significand128.parts[2] = midl;
+       significand128.parts[3] = low;
+
+       if (significand128.parts[0] == 0 && significand128.parts[1] == 0 &&
+           significand128.parts[2] == 0 && significand128.parts[3] == 0) {
+          is_zero = true;
+       } else if (significand128.parts[0] >= (1 << 17)) {
+          /* The significand is non-canonical or zero.
+           * In order to preserve compatibility with the densely packed decimal
+           * format, the maximum value for the significand of decimal128 is
+           * 1e34 - 1.  If the value is greater than 1e34 - 1, the IEEE 754
+           * standard dictates that the significand is interpreted as zero.
+           */
+          is_zero = true;
+       } else {
+          for (k = 3; k >= 0; k--) {
+             uint32_t least_digits = 0;
+             detail::bson_uint128_divide1B (
+                significand128, &significand128, &least_digits);
+
+             /* We now have the 9 least significant digits (in base 2). */
+             /* Convert and output to string. */
+             if (!least_digits) {
+                continue;
+             }
+
+             for (j = 8; j >= 0; j--) {
+                significand[k * 9 + j] = least_digits % 10;
+                least_digits /= 10;
+             }
+          }
+       }
+
+       /* Output format options: */
+       /* Scientific - [-]d.dddE(+/-)dd or [-]dE(+/-)dd */
+       /* Regular    - ddd.ddd */
+
+       if (is_zero) {
+          significand_digits = 1;
+          *significand_read = 0;
+       } else {
+          significand_digits = 36;
+          while (!(*significand_read)) {
+             significand_digits--;
+             significand_read++;
+          }
+       }
+
+       scientific_exponent = significand_digits - 1 + exponent;
+
+       /* The scientific exponent checks are dictated by the string conversion
+        * specification and are somewhat arbitrary cutoffs.
+        *
+        * We must check exponent > 0, because if this is the case, the number
+        * has trailing zeros.  However, we *cannot* output these trailing zeros,
+        * because doing so would change the precision of the value, and would
+        * change stored data if the string converted number is round tripped.
+        */
+       if (scientific_exponent < -6 || exponent > 0) {
+          /* Scientific format */
+          *(str_out++) = *(significand_read++) + '0';
+          significand_digits--;
+
+          if (significand_digits) {
+             *(str_out++) = '.';
+          }
+
+          for (i = 0; i < significand_digits && (str_out - first) < 36; i++) {
+             *(str_out++) = *(significand_read++) + '0';
+          }
+          /* Exponent */
+          *(str_out++) = 'E';
+          snprintf (str_out, 6, "%+d", scientific_exponent);
+       } else {
+          /* Regular format with no decimal place */
+          if (exponent >= 0) {
+             for (i = 0; i < significand_digits && (str_out - first) < 36; i++) {
+                *(str_out++) = *(significand_read++) + '0';
+             }
+             *str_out = '\0';
+          } else {
+             int32_t radix_position = significand_digits + exponent;
+
+             if (radix_position > 0) { /* non-zero digits before radix */
+                for (i = 0;
+                     i < radix_position && (str_out < last);
+                     i++) {
+                   *(str_out++) = *(significand_read++) + '0';
+                }
+             } else { /* leading zero before radix point */
+                *(str_out++) = '0';
+             }
+
+             *(str_out++) = '.';
+             while (radix_position++ < 0) { /* add leading zeros after radix */
+                *(str_out++) = '0';
+             }
+
+             for (i = 0;
+                  (i < significand_digits - (std::max) (radix_position - 1, 0)) &&
+                  (str_out < last);
+                  i++) {
+                *(str_out++) = *(significand_read++) + '0';
+             }
+             *str_out = '\0';
+          }
+       }
+    }
+
+
+
+    /**
+     *------------------------------------------------------------------------------
+     *
+     * bson_decimal128_from_string_w_len --
+     *
+     *    This function converts @string in the format [+-]ddd[.]ddd[E][+-]dddd to
+     *    decimal128.  Out of range values are converted to +/-Infinity.  Invalid
+     *    strings are converted to NaN. @len is the length of the string, or -1
+     *    meaning the string is null-terminated.
+     *
+     *    If more digits are provided than the available precision allows,
+     *    round to the nearest expressable decimal128 with ties going to even will
+     *    occur.
+     *
+     *    Note: @string must be ASCII only!
+     *
+     * Returns:
+     *    true on success, or false on failure. @dec will be NaN if @str was invalid
+     *    The &decimal128_t converted from @string at @dec.
+     *
+     * Side effects:
+     *    None.
+     *
+     *------------------------------------------------------------------------------
+     */
+
+    inline
+    bool decimal128_from_chars(const char* first, const char* last, decimal128_t& dec) 
+    {
+        int len = last - first;
+
+       bson_uint128_6464_t significand = {0};
+
+       const char* str_read = first; /* Read pointer for consuming str. */
+
+       /* Parsing state tracking */
+       bool is_negative = false;
+       bool saw_radix = false;
+       bool includes_sign = false; /* True if the input first contains a sign. */
+       bool found_nonzero = false;
+
+       size_t significant_digits = 0; /* Total number of significant digits
+                                       * (no leading or trailing zero) */
+       size_t ndigits_read = 0;       /* Total number of significand digits read */
+       size_t ndigits = 0;        /* Total number of digits (no leading zeros) */
+       size_t radix_position = 0; /* The number of the digits after radix */
+       size_t first_nonzero = 0;  /* The index of the first non-zero in *str* */
+
+       uint16_t digits[decimal128_limits::max_digits] = {0};
+       uint16_t ndigits_stored = 0;      /* The number of digits in digits */
+       uint16_t *digits_insert = digits; /* Insertion pointer for digits */
+       size_t first_digit = 0;           /* The index of the first non-zero digit */
+       size_t last_digit = 0;            /* The index of the last digit */
+
+       int32_t exponent = 0;
+       uint64_t significand_high = 0; /* The high 17 digits of the significand */
+       uint64_t significand_low = 0;  /* The low 17 digits of the significand */
+       uint16_t biased_exponent = 0;  /* The biased exponent */
+
+       dec.high = 0;
+       dec.low = 0;
+
+       if (*str_read == '+' || *str_read == '-') {
+          is_negative = *(str_read++) == '-';
+          includes_sign = true;
+       }
+
+       /* Check for Infinity or NaN */
+       if (!isdigit (*str_read) && *str_read != '.') {
+          if (detail::dec128_istreq (str_read, "inf") ||
+              detail::dec128_istreq (str_read, "infinity")) {
+              dec = is_negative ? decimal128_limits::neg_infinity : decimal128_limits::infinity;
+             return true;
+          } else if (detail::dec128_istreq (str_read, "nan")) {
+             dec = decimal128_limits::nan;
+             return true;
+          }
+
+          dec = decimal128_limits::nan;
+          return false;
+       }
+
+       /* Read digits */
+       while (((isdigit (*str_read) || *str_read == '.')) &&
+              (len == -1 || str_read < first + len)) {
+          if (*str_read == '.') {
+             if (saw_radix) {
+                dec = decimal128_limits::nan;
+                return false;
+             }
+
+             saw_radix = true;
+             str_read++;
+             continue;
+          }
+
+          if (ndigits_stored < 34) {
+             if (*str_read != '0' || found_nonzero) {
+                if (!found_nonzero) {
+                   first_nonzero = ndigits_read;
+                }
+
+                found_nonzero = true;
+                *(digits_insert++) = *(str_read) - '0'; /* Only store 34 digits */
+                ndigits_stored++;
+             }
+          }
+
+          if (found_nonzero) {
+             ndigits++;
+          }
+
+          if (saw_radix) {
+             radix_position++;
+          }
+
+          ndigits_read++;
+          str_read++;
+       }
+
+       if (saw_radix && !ndigits_read) {
+          dec = decimal128_limits::nan;
+          return false;
+       }
+
+       /* Read exponent if exists */
+       if (*str_read == 'e' || *str_read == 'E') {
+          int nread = 0;
+    #ifdef _MSC_VER
+    #define SSCANF sscanf_s
+    #else
+    #define SSCANF sscanf
+    #endif
+          int read_exponent = SSCANF (++str_read, "%d%n", &exponent, &nread);
+          str_read += nread;
+
+          if (!read_exponent || nread == 0) {
+             dec = decimal128_limits::nan;
+             return false;
+          }
+
+    #undef SSCANF
+       }
+
+       if ((len == -1 || str_read < first + len) && *str_read) {
+          dec = decimal128_limits::nan;
+          return false;
+       }
+
+       /* Done reading input. */
+       /* Find first non-zero digit in digits */
+       first_digit = 0;
+
+       if (!ndigits_stored) { /* value is zero */
+          first_digit = 0;
+          last_digit = 0;
+          digits[0] = 0;
+          ndigits = 1;
+          ndigits_stored = 1;
+          significant_digits = 0;
+       } else {
+          last_digit = ndigits_stored - 1;
+          significant_digits = ndigits;
+          /* Mark trailing zeros as non-significant */
+          while (first[first_nonzero + significant_digits - 1 + includes_sign +
+                        saw_radix] == '0') {
+             significant_digits--;
+          }
+       }
+
+
+       /* Normalization of exponent */
+       /* Correct exponent based on radix position, and shift significand as needed
+        */
+       /* to represent user input */
+
+       /* Overflow prevention */
+       if (exponent <= radix_position && radix_position - exponent > (1 << 14)) {
+          exponent = decimal128_limits::exponent_min;
+       } else {
+          exponent -= radix_position;
+       }
+
+       /* Attempt to normalize the exponent */
+       while (exponent > decimal128_limits::exponent_max) {
+          /* Shift exponent to significand and decrease */
+          last_digit++;
+
+          if (last_digit - first_digit > decimal128_limits::max_digits) {
+             /* The exponent is too great to shift into the significand. */
+             if (significant_digits == 0) {
+                /* Value is zero, we are allowed to clamp the exponent. */
+                exponent = decimal128_limits::exponent_max;
+                break;
+             }
+
+             /* Overflow is not permitted, error. */
+             dec = decimal128_limits::nan;
+             return false;
+          }
+
+          exponent--;
+       }
+
+       while (exponent < decimal128_limits::exponent_min || ndigits_stored < ndigits) {
+          /* Shift last digit */
+          if (last_digit == 0) {
+             /* underflow is not allowed, but zero clamping is */
+             if (significant_digits == 0) {
+                exponent = decimal128_limits::exponent_min;
+                break;
+             }
+
+             dec = decimal128_limits::nan;
+             return false;
+          }
+
+          if (ndigits_stored < ndigits) {
+             if (first[ndigits - 1 + includes_sign + saw_radix] - '0' != 0 &&
+                 significant_digits != 0) {
+                dec = decimal128_limits::nan;
+                return false;
+             }
+
+             ndigits--; /* adjust to match digits not stored */
+          } else {
+             if (digits[last_digit] != 0) {
+                /* Inexact rounding is not allowed. */
+                dec = decimal128_limits::nan;
+                return false;
+             }
+
+
+             last_digit--; /* adjust to round */
+          }
+
+          if (exponent < decimal128_limits::exponent_max) {
+             exponent++;
+          } else {
+             dec = decimal128_limits::nan;
+             return false;
+          }
+       }
+
+       /* Round */
+       /* We've normalized the exponent, but might still need to round. */
+       if (last_digit - first_digit + 1 < significant_digits) {
+          uint8_t round_digit;
+
+          /* There are non-zero digits after last_digit that need rounding. */
+          /* We round to nearest, ties to even */
+          round_digit =
+             first[first_nonzero + last_digit + includes_sign + saw_radix + 1] -
+             '0';
+
+          if (round_digit != 0) {
+             /* Inexact (non-zero) rounding is not allowed */
+             dec = decimal128_limits::nan;
+             return false;
+          }
+       }
+
+       /* Encode significand */
+       significand_high = 0,   /* The high 17 digits of the significand */
+          significand_low = 0; /* The low 17 digits of the significand */
+
+       if (significant_digits == 0) { /* read a zero */
+          significand_high = 0;
+          significand_low = 0;
+       } else if (last_digit - first_digit < 17) {
+          size_t d_idx = first_digit;
+          significand_low = digits[d_idx++];
+
+          for (; d_idx <= last_digit; d_idx++) {
+             significand_low *= 10;
+             significand_low += digits[d_idx];
+             significand_high = 0;
+          }
+       } else {
+          size_t d_idx = first_digit;
+          significand_high = digits[d_idx++];
+
+          for (; d_idx <= last_digit - 17; d_idx++) {
+             significand_high *= 10;
+             significand_high += digits[d_idx];
+          }
+
+          significand_low = digits[d_idx++];
+
+          for (; d_idx <= last_digit; d_idx++) {
+             significand_low *= 10;
+             significand_low += digits[d_idx];
+          }
+       }
+
+       detail::mul_64x64 (significand_high, 100000000000000000ull, &significand);
+       significand.low += significand_low;
+
+       if (significand.low < significand_low) {
+          significand.high += 1;
+       }
+
+
+       biased_exponent = (exponent + (int16_t) decimal128_limits::exponent_bias);
+
+       /* Encode combination, exponent, and significand. */
+       if ((significand.high >> 49) & 1) {
+          /* Encode '11' into bits 1 to 3 */
+          dec.high |= (0x3ull << 61);
+          dec.high |= (biased_exponent & 0x3fffull) << 47;
+          dec.high |= significand.high & 0x7fffffffffffull;
+       } else {
+          dec.high |= (biased_exponent & 0x3fffull) << 49;
+          dec.high |= significand.high & 0x1ffffffffffffull;
+       }
+
+       dec.low = significand.low;
+
+       /* Encode sign */
+       if (is_negative) {
+          dec.high |= 0x8000000000000000ull;
+       }
+
+       return true;
+    }
+
+} // namespace bson
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_encoder.hpp b/include/jsoncons_ext/bson/bson_encoder.hpp
new file mode 100644
index 0000000..4569f06
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_encoder.hpp
@@ -0,0 +1,585 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_ENCODER_HPP
+#define JSONCONS_BSON_BSON_ENCODER_HPP
+
+#include <string>
+#include <vector>
+#include <limits> // std::numeric_limits
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/sink.hpp>
+#include <jsoncons/detail/parse_number.hpp>
+#include <jsoncons_ext/bson/bson_type.hpp>
+#include <jsoncons_ext/bson/bson_error.hpp>
+#include <jsoncons_ext/bson/bson_options.hpp>
+#include <jsoncons_ext/bson/bson_decimal128.hpp>
+#include <jsoncons_ext/bson/bson_oid.hpp>
+
+namespace jsoncons { namespace bson {
+
+template<class Sink=jsoncons::binary_stream_sink,class Allocator=std::allocator<char>>
+class basic_bson_encoder final : public basic_json_visitor<char>
+{
+    enum class decimal_parse_state { start, integer, exp1, exp2, fraction1 };
+    static constexpr int64_t nanos_in_milli = 1000000;
+    static constexpr int64_t nanos_in_second = 1000000000;
+    static constexpr int64_t millis_in_second = 1000;
+public:
+    using allocator_type = Allocator;
+    using char_type = char;
+    using typename basic_json_visitor<char>::string_view_type;
+    using sink_type = Sink;
+
+private:
+    struct stack_item
+    {
+        jsoncons::bson::bson_container_type type_;
+        std::size_t offset_;
+        std::size_t name_offset_;
+        std::size_t index_;
+
+        stack_item(jsoncons::bson::bson_container_type type, std::size_t offset) noexcept
+           : type_(type), offset_(offset), name_offset_(0), index_(0)
+        {
+        }
+
+        std::size_t offset() const
+        {
+            return offset_;
+        }
+
+        std::size_t member_offset() const
+        {
+            return name_offset_;
+        }
+
+        void member_offset(std::size_t offset) 
+        {
+            name_offset_ = offset;
+        }
+
+        std::size_t next_index()
+        {
+            return index_++;
+        }
+
+        bool is_object() const
+        {
+            return type_ == jsoncons::bson::bson_container_type::document;
+        }
+
+
+    };
+
+    sink_type sink_;
+    const bson_encode_options options_;
+    allocator_type alloc_;
+
+    std::vector<stack_item> stack_;
+    std::vector<uint8_t> buffer_;
+    int nesting_depth_;
+
+    // Noncopyable and nonmoveable
+    basic_bson_encoder(const basic_bson_encoder&) = delete;
+    basic_bson_encoder& operator=(const basic_bson_encoder&) = delete;
+public:
+    explicit basic_bson_encoder(Sink&& sink, 
+                                const Allocator& alloc = Allocator())
+       : basic_bson_encoder(std::forward<Sink>(sink),
+                            bson_encode_options(),
+                            alloc)
+    {
+    }
+
+    explicit basic_bson_encoder(Sink&& sink, 
+                                const bson_encode_options& options, 
+                                const Allocator& alloc = Allocator())
+       : sink_(std::forward<Sink>(sink)),
+         options_(options),
+         alloc_(alloc), 
+         nesting_depth_(0)
+    {
+    }
+
+    ~basic_bson_encoder() noexcept
+    {
+        sink_.flush();
+    }
+
+    void reset()
+    {
+        stack_.clear();
+        buffer_.clear();
+        nesting_depth_ = 0;
+    }
+
+    void reset(Sink&& sink)
+    {
+        sink_ = std::move(sink);
+        reset();
+    }
+
+private:
+    // Implementing methods
+
+    void visit_flush() override
+    {
+        sink_.flush();
+    }
+
+    bool visit_begin_object(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = bson_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        if (buffer_.size() > 0)
+        {
+            if (stack_.empty())
+            {
+                ec = bson_errc::expected_bson_document;
+                return false;
+            }
+            before_value(jsoncons::bson::bson_type::document_type);
+        }
+
+        stack_.emplace_back(jsoncons::bson::bson_container_type::document, buffer_.size());
+        buffer_.insert(buffer_.end(), sizeof(int32_t), 0);
+
+        return true;
+    }
+
+    bool visit_end_object(const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        --nesting_depth_;
+
+        buffer_.push_back(0x00);
+
+        std::size_t length = buffer_.size() - stack_.back().offset();
+        binary::native_to_little(static_cast<uint32_t>(length), buffer_.begin()+stack_.back().offset());
+
+        stack_.pop_back();
+        if (stack_.empty())
+        {
+            for (auto c : buffer_)
+            {
+                sink_.push_back(c);
+            }
+        }
+        return true;
+    }
+
+    bool visit_begin_array(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = bson_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        if (buffer_.size() > 0)
+        {
+            if (stack_.empty())
+            {
+                ec = bson_errc::expected_bson_document;
+                return false;
+            }
+            before_value(jsoncons::bson::bson_type::array_type);
+        }
+        stack_.emplace_back(jsoncons::bson::bson_container_type::array, buffer_.size());
+        buffer_.insert(buffer_.end(), sizeof(int32_t), 0);
+        return true;
+    }
+
+    bool visit_end_array(const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        --nesting_depth_;
+
+        buffer_.push_back(0x00);
+
+        std::size_t length = buffer_.size() - stack_.back().offset();
+        binary::native_to_little(static_cast<uint32_t>(length), buffer_.begin()+stack_.back().offset());
+
+        stack_.pop_back();
+        if (stack_.empty())
+        {
+            for (auto c : buffer_)
+            {
+                sink_.push_back(c);
+            }
+        }
+        return true;
+    }
+
+    bool visit_key(const string_view_type& name, const ser_context&, std::error_code&) override
+    {
+        stack_.back().member_offset(buffer_.size());
+        buffer_.push_back(0x00); // reserve space for code
+        for (auto c : name)
+        {
+            buffer_.push_back(c);
+        }
+        buffer_.push_back(0x00);
+        return true;
+    }
+
+    bool visit_null(semantic_tag tag, const ser_context&, std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+        switch (tag)
+        {
+            case semantic_tag::undefined:
+                before_value(jsoncons::bson::bson_type::undefined_type);
+                break;
+            default:
+                before_value(jsoncons::bson::bson_type::null_type);
+                break;
+        }
+        return true;
+    }
+
+    bool visit_bool(bool val, semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+        before_value(jsoncons::bson::bson_type::bool_type);
+        if (val)
+        {
+            buffer_.push_back(0x01);
+        }
+        else
+        {
+            buffer_.push_back(0x00);
+        }
+
+        return true;
+    }
+
+    bool visit_string(const string_view_type& sv, semantic_tag tag, const ser_context&, std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+
+        switch (tag)
+        {
+            case semantic_tag::float128:
+            {
+                before_value(jsoncons::bson::bson_type::decimal128_type);
+                decimal128_t dec;
+                auto rc = decimal128_from_chars(sv.data(), sv.data()+sv.size(), dec);
+                if (rc.ec != std::errc())
+                {
+                    ec = bson_errc::invalid_decimal128_string;
+                    return false;
+                }
+                binary::native_to_little(dec.low,std::back_inserter(buffer_));
+                binary::native_to_little(dec.high,std::back_inserter(buffer_));
+                break;
+            }
+            case semantic_tag::id:
+            {
+                before_value(jsoncons::bson::bson_type::object_id_type);
+                oid_t oid(sv);
+                for (auto b : oid)
+                {
+                    buffer_.push_back(b);
+                }
+                break;
+            }
+            case semantic_tag::regex:
+            {
+                before_value(jsoncons::bson::bson_type::regex_type);
+                std::size_t first = sv.find_first_of('/');
+                std::size_t last = sv.find_last_of('/');
+                if (first == string_view::npos || last == string_view::npos || first == last)
+                {
+                    ec = bson_errc::invalid_regex_string;
+                    return false;
+                }
+                string_view regex = sv.substr(first+1,last-1);
+                for (auto c : regex)
+                {
+                    buffer_.push_back(c);
+                }
+                buffer_.push_back(0x00);
+                string_view options = sv.substr(last+1);
+                for (auto c : options)
+                {
+                    buffer_.push_back(c);
+                }
+                buffer_.push_back(0x00);
+                break;
+            }
+            default:
+                switch (tag)
+                {
+                    case semantic_tag::code:
+                        before_value(jsoncons::bson::bson_type::javascript_type);
+                        break;
+                    default:
+                        before_value(jsoncons::bson::bson_type::string_type);
+                        break;
+                }
+                std::size_t offset = buffer_.size();
+                buffer_.insert(buffer_.end(), sizeof(int32_t), 0);
+                std::size_t string_offset = buffer_.size();
+                auto sink = unicode_traits::validate(sv.data(), sv.size());
+                if (sink.ec != unicode_traits::conv_errc())
+                {
+                    ec = bson_errc::invalid_utf8_text_string;
+                    return false;
+                }
+                for (auto c : sv)
+                {
+                    buffer_.push_back(c);
+                }
+                buffer_.push_back(0x00);
+                std::size_t length = buffer_.size() - string_offset;
+                binary::native_to_little(static_cast<uint32_t>(length), buffer_.begin()+offset);
+                break;
+        }
+
+        return true;
+    }
+
+    bool visit_byte_string(const byte_string_view& b, 
+                           semantic_tag, 
+                           const ser_context&,
+                           std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+        before_value(jsoncons::bson::bson_type::binary_type);
+
+        std::size_t offset = buffer_.size();
+        buffer_.insert(buffer_.end(), sizeof(int32_t), 0);
+        std::size_t string_offset = buffer_.size();
+
+        buffer_.push_back(0x80); // default subtype
+
+        for (auto c : b)
+        {
+            buffer_.push_back(c);
+        }
+        std::size_t length = buffer_.size() - string_offset - 1;
+        binary::native_to_little(static_cast<uint32_t>(length), buffer_.begin()+offset);
+
+        return true;
+    }
+
+    bool visit_byte_string(const byte_string_view& b, 
+                           uint64_t ext_tag, 
+                           const ser_context&,
+                           std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+        before_value(jsoncons::bson::bson_type::binary_type);
+
+        std::size_t offset = buffer_.size();
+        buffer_.insert(buffer_.end(), sizeof(int32_t), 0);
+        std::size_t string_offset = buffer_.size();
+
+        buffer_.push_back(static_cast<uint8_t>(ext_tag)); // default subtype
+
+        for (auto c : b)
+        {
+            buffer_.push_back(c);
+        }
+        std::size_t length = buffer_.size() - string_offset - 1;
+        binary::native_to_little(static_cast<uint32_t>(length), buffer_.begin()+offset);
+
+        return true;
+    }
+
+    bool visit_int64(int64_t val, 
+                     semantic_tag tag, 
+                     const ser_context&,
+                     std::error_code& ec) override
+    {
+        static constexpr int64_t min_value_div_1000 = (std::numeric_limits<int64_t>::min)() / 1000;
+        static constexpr int64_t max_value_div_1000 = (std::numeric_limits<int64_t>::max)() / 1000;
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+
+        switch (tag)
+        {
+            case semantic_tag::epoch_second:
+                if (val < min_value_div_1000)
+                {
+                    ec = bson_errc::datetime_too_small;
+                    return false;
+                }
+                if (val > max_value_div_1000)
+                {
+                    ec = bson_errc::datetime_too_large;
+                    return false;
+                }
+                before_value(jsoncons::bson::bson_type::datetime_type);
+                binary::native_to_little(val*millis_in_second,std::back_inserter(buffer_));
+                return true;
+            case semantic_tag::epoch_milli:
+                before_value(jsoncons::bson::bson_type::datetime_type);
+                binary::native_to_little(val,std::back_inserter(buffer_));
+                return true;
+            case semantic_tag::epoch_nano:
+                before_value(jsoncons::bson::bson_type::datetime_type);
+                if (val != 0)
+                {
+                    val /= nanos_in_milli;
+                }
+                binary::native_to_little(static_cast<int64_t>(val),std::back_inserter(buffer_));
+                return true;
+            default:
+            {
+                if (val >= (std::numeric_limits<int32_t>::lowest)() && val <= (std::numeric_limits<int32_t>::max)())
+                {
+                    before_value(jsoncons::bson::bson_type::int32_type);
+                    binary::native_to_little(static_cast<uint32_t>(val),std::back_inserter(buffer_));
+                }
+                else 
+                {
+                    before_value(jsoncons::bson::bson_type::int64_type);
+                    binary::native_to_little(static_cast<int64_t>(val),std::back_inserter(buffer_));
+                }
+                return true;
+            }
+        }
+    }
+
+    bool visit_uint64(uint64_t val, 
+                      semantic_tag tag, 
+                      const ser_context&,
+                      std::error_code& ec) override
+    {
+        static constexpr uint64_t max_value_div_1000 = (std::numeric_limits<uint64_t>::max)() / 1000;
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+
+        switch (tag)
+        {
+            case semantic_tag::epoch_second:
+                if (val > max_value_div_1000)
+                {
+                    ec = bson_errc::datetime_too_large;
+                    return false;
+                }
+                before_value(jsoncons::bson::bson_type::datetime_type);
+                binary::native_to_little(static_cast<int64_t>(val*millis_in_second),std::back_inserter(buffer_));
+                return true;
+            case semantic_tag::epoch_milli:
+                before_value(jsoncons::bson::bson_type::datetime_type);
+                binary::native_to_little(static_cast<int64_t>(val),std::back_inserter(buffer_));
+                return true;
+            case semantic_tag::epoch_nano:
+                before_value(jsoncons::bson::bson_type::datetime_type);
+                if (val != 0)
+                {
+                    val /= nanos_in_second;
+                }
+                binary::native_to_little(static_cast<int64_t>(val),std::back_inserter(buffer_));
+                return true;
+            default:
+            {
+                bool more;
+                if (val <= static_cast<uint64_t>((std::numeric_limits<int32_t>::max)()))
+                {
+                    before_value(jsoncons::bson::bson_type::int32_type);
+                    binary::native_to_little(static_cast<uint32_t>(val),std::back_inserter(buffer_));
+                    more = true;
+                }
+                else if (val <= static_cast<uint64_t>((std::numeric_limits<int64_t>::max)()))
+                {
+                    before_value(jsoncons::bson::bson_type::int64_type);
+                    binary::native_to_little(static_cast<uint64_t>(val),std::back_inserter(buffer_));
+                    more = true;
+                }
+                else
+                {
+                    ec = bson_errc::number_too_large;
+                    more = false;
+                }
+                return more;
+            }
+        }
+    }
+
+    bool visit_double(double val, 
+                      semantic_tag,
+                      const ser_context&,
+                      std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            ec = bson_errc::expected_bson_document;
+            return false;
+        }
+        before_value(jsoncons::bson::bson_type::double_type);
+        binary::native_to_little(val,std::back_inserter(buffer_));
+        return true;
+    }
+
+    void before_value(uint8_t code) 
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        if (stack_.back().is_object())
+        {
+            buffer_[stack_.back().member_offset()] = code;
+        }
+        else
+        {
+            buffer_.push_back(code);
+            std::string name = std::to_string(stack_.back().next_index());
+            buffer_.insert(buffer_.end(), name.begin(), name.end());
+            buffer_.push_back(0x00);
+        }
+    }
+};
+
+using bson_stream_encoder = basic_bson_encoder<jsoncons::binary_stream_sink>;
+using bson_bytes_encoder = basic_bson_encoder<jsoncons::bytes_sink<std::vector<uint8_t>>>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+template<class Sink=jsoncons::binary_stream_sink>
+using basic_bson_serializer = basic_bson_encoder<Sink>; 
+
+JSONCONS_DEPRECATED_MSG("Instead, use bson_stream_encoder") typedef bson_stream_encoder bson_encoder;
+JSONCONS_DEPRECATED_MSG("Instead, use bson_stream_encoder") typedef bson_stream_encoder bson_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use bson_bytes_encoder")  typedef bson_bytes_encoder bson_buffer_serializer;
+
+#endif
+
+}}
+#endif
diff --git a/include/jsoncons_ext/bson/bson_error.hpp b/include/jsoncons_ext/bson/bson_error.hpp
new file mode 100644
index 0000000..85cf24d
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_error.hpp
@@ -0,0 +1,103 @@
+/// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_ERROR_HPP
+#define JSONCONS_BSON_BSON_ERROR_HPP
+
+#include <system_error>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace bson {
+
+enum class bson_errc
+{
+    success = 0,
+    unexpected_eof = 1,
+    source_error,
+    invalid_utf8_text_string,
+    max_nesting_depth_exceeded,
+    string_length_is_non_positive,
+    length_is_negative,
+    number_too_large,
+    invalid_decimal128_string,
+    datetime_too_small,
+    datetime_too_large,
+    expected_bson_document,
+    invalid_regex_string,
+    size_mismatch,
+    unknown_type
+};
+
+class bson_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/bson";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<bson_errc>(ev))
+        {
+            case bson_errc::unexpected_eof:
+                return "Unexpected end of file";
+            case bson_errc::source_error:
+                return "Source error";
+            case bson_errc::invalid_utf8_text_string:
+                return "Illegal UTF-8 encoding in text string";
+            case bson_errc::max_nesting_depth_exceeded:
+                return "Data item nesting exceeds limit in options";
+            case bson_errc::string_length_is_non_positive:
+                return "Request for the length of a string returned a non-positive result";
+            case bson_errc::length_is_negative:
+                return "Request for the length of a binary returned a negative result";
+            case bson_errc::unknown_type:
+                return "An unknown type was found in the stream";
+            case bson_errc::number_too_large:
+                return "Number too large";
+            case bson_errc::invalid_decimal128_string:
+                return "Invalid decimal128 string";
+            case bson_errc::datetime_too_large:
+                return "datetime too large";
+            case bson_errc::datetime_too_small:
+                return "datetime too small";
+            case bson_errc::expected_bson_document:
+                return "Expected BSON document";
+            case bson_errc::invalid_regex_string:
+                return "Invalid regex string";
+            case bson_errc::size_mismatch:
+                return "Document or array size doesn't match bytes read";
+            default:
+                return "Unknown BSON parser error";
+        }
+    }
+};
+
+inline
+const std::error_category& bson_error_category()
+{
+  static bson_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(bson_errc result)
+{
+    return std::error_code(static_cast<int>(result),bson_error_category());
+}
+
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::bson::bson_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_oid.hpp b/include/jsoncons_ext/bson/bson_oid.hpp
new file mode 100644
index 0000000..065d8da
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_oid.hpp
@@ -0,0 +1,245 @@
+#ifndef JSONCONS_BSON_BSON_OID_HPP
+#define JSONCONS_BSON_BSON_OID_HPP
+
+/*
+ *  Implements class oid_t and non member function bson_oid_to_string
+ *  
+ *  Based on the libjson functions bson_oid_to_string 
+ *  and bson_oid_init_from_string_unsafe , available at
+ *  https://github.com/mongodb/mongo-c-driver/blob/master/src/libbson/src/bson/bson-oid.h
+ *  and https://github.com/mongodb/mongo-c-driver/blob/master/src/libbson/src/bson/bson-oid.c
+ *  
+*/
+
+/*
+ * Copyright 2015 MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cstdlib>
+#include <cstring>
+#include <ctype.h>
+#include <system_error>
+#include <algorithm>
+#include <string>
+#include <type_traits>
+#include <array>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace bson {
+
+    class oid_t
+    {
+        std::array<uint8_t,12> bytes_;
+    public:
+        using iterator = std::array<uint8_t,12>::iterator;
+        using const_iterator = std::array<uint8_t,12>::const_iterator;
+
+        oid_t(const std::array<uint8_t,12>& bytes)
+            : bytes_(bytes)
+        {
+        }
+        oid_t(uint8_t data[12])
+        {
+            std::memcpy(bytes_.data(),data,12);
+        }
+
+        oid_t(const string_view& str)
+        {
+            for (std::size_t i = 0; i < bytes_.size(); i++) 
+            {
+               bytes_[i] = ((parse_hex_char (str[2 * i]) << 4) |
+                           (parse_hex_char (str[2 * i + 1])));
+            }
+        }
+
+        const uint8_t* data() const
+        {
+            return bytes_.data();
+        }
+
+        std::size_t size() const
+        {
+            return bytes_.size();
+        }
+
+        iterator begin()
+        {
+            return bytes_.begin();
+        }
+
+        iterator end()
+        {
+            return bytes_.end();
+        }
+
+        const_iterator begin() const
+        {
+            return bytes_.begin();
+        }
+
+        const_iterator end() const
+        {
+            return bytes_.end();
+        }
+
+    private:
+
+        static uint8_t parse_hex_char (char hex)
+        {
+           switch (hex) {
+           case '0':
+              return 0;
+           case '1':
+              return 1;
+           case '2':
+              return 2;
+           case '3':
+              return 3;
+           case '4':
+              return 4;
+           case '5':
+              return 5;
+           case '6':
+              return 6;
+           case '7':
+              return 7;
+           case '8':
+              return 8;
+           case '9':
+              return 9;
+           case 'a':
+           case 'A':
+              return 0xa;
+           case 'b':
+           case 'B':
+              return 0xb;
+           case 'c':
+           case 'C':
+              return 0xc;
+           case 'd':
+           case 'D':
+              return 0xd;
+           case 'e':
+           case 'E':
+              return 0xe;
+           case 'f':
+           case 'F':
+              return 0xf;
+           default:
+              return 0;
+           }
+        }
+    };
+
+    namespace detail {
+
+        inline
+        const uint16_t* get_hex_char_pairs(std::true_type) // big endian
+        {
+            static const uint16_t hex_char_pairs[] = {
+               12336, 12337, 12338, 12339, 12340, 12341, 12342, 12343, 12344, 12345, 12385,
+               12386, 12387, 12388, 12389, 12390, 12592, 12593, 12594, 12595, 12596, 12597,
+               12598, 12599, 12600, 12601, 12641, 12642, 12643, 12644, 12645, 12646, 12848,
+               12849, 12850, 12851, 12852, 12853, 12854, 12855, 12856, 12857, 12897, 12898,
+               12899, 12900, 12901, 12902, 13104, 13105, 13106, 13107, 13108, 13109, 13110,
+               13111, 13112, 13113, 13153, 13154, 13155, 13156, 13157, 13158, 13360, 13361,
+               13362, 13363, 13364, 13365, 13366, 13367, 13368, 13369, 13409, 13410, 13411,
+               13412, 13413, 13414, 13616, 13617, 13618, 13619, 13620, 13621, 13622, 13623,
+               13624, 13625, 13665, 13666, 13667, 13668, 13669, 13670, 13872, 13873, 13874,
+               13875, 13876, 13877, 13878, 13879, 13880, 13881, 13921, 13922, 13923, 13924,
+               13925, 13926, 14128, 14129, 14130, 14131, 14132, 14133, 14134, 14135, 14136,
+               14137, 14177, 14178, 14179, 14180, 14181, 14182, 14384, 14385, 14386, 14387,
+               14388, 14389, 14390, 14391, 14392, 14393, 14433, 14434, 14435, 14436, 14437,
+               14438, 14640, 14641, 14642, 14643, 14644, 14645, 14646, 14647, 14648, 14649,
+               14689, 14690, 14691, 14692, 14693, 14694, 24880, 24881, 24882, 24883, 24884,
+               24885, 24886, 24887, 24888, 24889, 24929, 24930, 24931, 24932, 24933, 24934,
+               25136, 25137, 25138, 25139, 25140, 25141, 25142, 25143, 25144, 25145, 25185,
+               25186, 25187, 25188, 25189, 25190, 25392, 25393, 25394, 25395, 25396, 25397,
+               25398, 25399, 25400, 25401, 25441, 25442, 25443, 25444, 25445, 25446, 25648,
+               25649, 25650, 25651, 25652, 25653, 25654, 25655, 25656, 25657, 25697, 25698,
+               25699, 25700, 25701, 25702, 25904, 25905, 25906, 25907, 25908, 25909, 25910,
+               25911, 25912, 25913, 25953, 25954, 25955, 25956, 25957, 25958, 26160, 26161,
+               26162, 26163, 26164, 26165, 26166, 26167, 26168, 26169, 26209, 26210, 26211,
+               26212, 26213, 26214};
+
+            return hex_char_pairs;
+        }
+
+        inline
+        const uint16_t* get_hex_char_pairs(std::false_type) // little endian
+        {
+            static const uint16_t hex_char_pairs[] = {
+                12336, 12592, 12848, 13104, 13360, 13616, 13872, 14128, 14384, 14640, 24880,
+                25136, 25392, 25648, 25904, 26160, 12337, 12593, 12849, 13105, 13361, 13617,
+                13873, 14129, 14385, 14641, 24881, 25137, 25393, 25649, 25905, 26161, 12338,
+                12594, 12850, 13106, 13362, 13618, 13874, 14130, 14386, 14642, 24882, 25138,
+                25394, 25650, 25906, 26162, 12339, 12595, 12851, 13107, 13363, 13619, 13875,
+                14131, 14387, 14643, 24883, 25139, 25395, 25651, 25907, 26163, 12340, 12596,
+                12852, 13108, 13364, 13620, 13876, 14132, 14388, 14644, 24884, 25140, 25396,
+                25652, 25908, 26164, 12341, 12597, 12853, 13109, 13365, 13621, 13877, 14133,
+                14389, 14645, 24885, 25141, 25397, 25653, 25909, 26165, 12342, 12598, 12854,
+                13110, 13366, 13622, 13878, 14134, 14390, 14646, 24886, 25142, 25398, 25654,
+                25910, 26166, 12343, 12599, 12855, 13111, 13367, 13623, 13879, 14135, 14391,
+                14647, 24887, 25143, 25399, 25655, 25911, 26167, 12344, 12600, 12856, 13112,
+                13368, 13624, 13880, 14136, 14392, 14648, 24888, 25144, 25400, 25656, 25912,
+                26168, 12345, 12601, 12857, 13113, 13369, 13625, 13881, 14137, 14393, 14649,
+                24889, 25145, 25401, 25657, 25913, 26169, 12385, 12641, 12897, 13153, 13409,
+                13665, 13921, 14177, 14433, 14689, 24929, 25185, 25441, 25697, 25953, 26209,
+                12386, 12642, 12898, 13154, 13410, 13666, 13922, 14178, 14434, 14690, 24930,
+                25186, 25442, 25698, 25954, 26210, 12387, 12643, 12899, 13155, 13411, 13667,
+                13923, 14179, 14435, 14691, 24931, 25187, 25443, 25699, 25955, 26211, 12388,
+                12644, 12900, 13156, 13412, 13668, 13924, 14180, 14436, 14692, 24932, 25188,
+                25444, 25700, 25956, 26212, 12389, 12645, 12901, 13157, 13413, 13669, 13925,
+                14181, 14437, 14693, 24933, 25189, 25445, 25701, 25957, 26213, 12390, 12646,
+                12902, 13158, 13414, 13670, 13926, 14182, 14438, 14694, 24934, 25190, 25446,
+                25702, 25958, 26214};
+
+            return hex_char_pairs;
+        }
+
+        inline
+        void init_hex_char_pairs(const oid_t& oid, uint16_t* data)
+        {
+            const uint8_t* bytes = oid.data();
+            const uint16_t* gHexCharPairs = get_hex_char_pairs(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>());
+
+            data[0] = gHexCharPairs[bytes[0]];
+            data[1] = gHexCharPairs[bytes[1]];
+            data[2] = gHexCharPairs[bytes[2]];
+            data[3] = gHexCharPairs[bytes[3]];
+            data[4] = gHexCharPairs[bytes[4]];
+            data[5] = gHexCharPairs[bytes[5]];
+            data[6] = gHexCharPairs[bytes[6]];
+            data[7] = gHexCharPairs[bytes[7]];
+            data[8] = gHexCharPairs[bytes[8]];
+            data[9] = gHexCharPairs[bytes[9]];
+            data[10] = gHexCharPairs[bytes[10]];
+            data[11] = gHexCharPairs[bytes[11]];
+        }
+
+    } // namsepace detail
+
+    template <typename StringT>
+    inline 
+    void to_string(const oid_t& oid, StringT& s)
+    {
+        s.resize(24);
+        detail::init_hex_char_pairs(oid, reinterpret_cast<uint16_t*>(&s[0]));
+    }
+
+} // namespace bson
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_options.hpp b/include/jsoncons_ext/bson/bson_options.hpp
new file mode 100644
index 0000000..0e4620e
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_options.hpp
@@ -0,0 +1,75 @@
+// Copyright 2019 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_OPTIONS_HPP
+#define JSONCONS_BSON_BSON_OPTIONS_HPP
+
+#include <string>
+#include <limits> // std::numeric_limits
+#include <cwchar>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons_ext/bson/bson_type.hpp>
+
+namespace jsoncons { namespace bson {
+
+class bson_options;
+
+class bson_options_common
+{
+    friend class bson_options;
+
+    int max_nesting_depth_;
+protected:
+    virtual ~bson_options_common() = default;
+
+    bson_options_common()
+        : max_nesting_depth_(1024)
+    {
+    }
+
+    bson_options_common(const bson_options_common&) = default;
+    bson_options_common& operator=(const bson_options_common&) = default;
+    bson_options_common(bson_options_common&&) = default;
+    bson_options_common& operator=(bson_options_common&&) = default;
+public:
+    int max_nesting_depth() const 
+    {
+        return max_nesting_depth_;
+    }
+};
+
+class bson_decode_options : public virtual bson_options_common
+{
+    friend class bson_options;
+public:
+    bson_decode_options()
+    {
+    }
+};
+
+class bson_encode_options : public virtual bson_options_common
+{
+    friend class bson_options;
+public:
+    bson_encode_options()
+    {
+    }
+};
+
+class bson_options final : public bson_decode_options, public bson_encode_options
+{
+public:
+    using bson_options_common::max_nesting_depth;
+
+    bson_options& max_nesting_depth(int value)
+    {
+        this->max_nesting_depth_ = value;
+        return *this;
+    }
+};
+
+}}
+#endif
diff --git a/include/jsoncons_ext/bson/bson_parser.hpp b/include/jsoncons_ext/bson/bson_parser.hpp
new file mode 100644
index 0000000..2dc6e75
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_parser.hpp
@@ -0,0 +1,645 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_PARSER_HPP
+#define JSONCONS_BSON_BSON_PARSER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/bson/bson_type.hpp>
+#include <jsoncons_ext/bson/bson_decimal128.hpp>
+#include <jsoncons_ext/bson/bson_error.hpp>
+#include <jsoncons_ext/bson/bson_options.hpp>
+#include <jsoncons_ext/bson/bson_oid.hpp>
+
+namespace jsoncons { namespace bson {
+
+enum class parse_mode {root,accept,document,array,value};
+
+struct parse_state 
+{
+    parse_mode mode; 
+    std::size_t length;
+    std::size_t pos;
+    uint8_t type;
+    std::size_t index;
+
+    parse_state(parse_mode mode_, std::size_t length_, std::size_t pos_, uint8_t type_ = 0) noexcept
+        : mode(mode_), length(length_), pos(pos_), type(type_), index(0)
+    {
+    }
+
+    parse_state(const parse_state&) = default;
+    parse_state(parse_state&&) = default;
+    parse_state& operator=(const parse_state&) = default;
+    parse_state& operator=(parse_state&&) = default;
+};
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_bson_parser : public ser_context
+{
+    using char_type = char;
+    using char_traits_type = std::char_traits<char>;
+    using temp_allocator_type = Allocator;
+    using char_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<char_type>;                  
+    using byte_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<uint8_t>;                  
+    using parse_state_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<parse_state>;                         
+
+    Source source_;
+    bson_decode_options options_;
+    bool more_;
+    bool done_;
+    std::vector<uint8_t,byte_allocator_type> bytes_buffer_;
+    std::basic_string<char,std::char_traits<char>,char_allocator_type> text_buffer_;
+    std::vector<parse_state,parse_state_allocator_type> state_stack_;
+public:
+    template <class Sourceable>
+    basic_bson_parser(Sourceable&& source,
+                      const bson_decode_options& options = bson_decode_options(),
+                      const Allocator alloc = Allocator())
+       : source_(std::forward<Sourceable>(source)), 
+         options_(options),
+         more_(true), 
+         done_(false),
+         text_buffer_(alloc),
+         state_stack_(alloc)
+    {
+        state_stack_.emplace_back(parse_mode::root,0,0);
+    }
+
+    void restart()
+    {
+        more_ = true;
+    }
+
+    void reset()
+    {
+        more_ = true;
+        done_ = false;
+        bytes_buffer_.clear();
+        text_buffer_.clear();
+        state_stack_.clear();
+        state_stack_.emplace_back(parse_mode::root,0,0);
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        source_ = std::forward<Sourceable>(source);
+        reset();
+    }
+
+    bool done() const
+    {
+        return done_;
+    }
+
+    bool stopped() const
+    {
+        return !more_;
+    }
+
+    std::size_t line() const override
+    {
+        return 0;
+    }
+
+    std::size_t column() const override
+    {
+        return source_.position();
+    }
+
+    void array_expected(json_visitor& visitor, std::error_code& ec)
+    {
+        if (state_stack_.size() == 2 && state_stack_.back().mode == parse_mode::document)
+        {
+            state_stack_.back().mode = parse_mode::array;
+            more_ = visitor.begin_array(semantic_tag::none, *this, ec);
+        }
+    }
+
+    void parse(json_visitor& visitor, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(source_.is_error()))
+        {
+            ec = bson_errc::source_error;
+            more_ = false;
+            return;
+        }
+        
+        while (!done_ && more_)
+        {
+            switch (state_stack_.back().mode)
+            {
+                case parse_mode::root:
+                    state_stack_.back().mode = parse_mode::accept;
+                    begin_document(visitor, ec);
+                    break;
+                case parse_mode::document:
+                {
+                    uint8_t type;
+                    std::size_t n = source_.read(&type, 1);
+                    state_stack_.back().pos += n;
+                    if (JSONCONS_UNLIKELY(n != 1))
+                    {
+                        ec = bson_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (type != 0x00)
+                    {
+                        read_e_name(visitor,jsoncons::bson::bson_container_type::document,ec);
+                        state_stack_.back().mode = parse_mode::value;
+                        state_stack_.back().type = type;
+                    }
+                    else
+                    {
+                        end_document(visitor,ec);
+                    }
+                    break;
+                }
+                case parse_mode::array:
+                {
+                    uint8_t type;
+                    std::size_t n = source_.read(&type, 1);
+                    state_stack_.back().pos += n;
+                    if (JSONCONS_UNLIKELY(n != 1))
+                    {
+                        ec = bson_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (type != 0x00)
+                    {
+                        read_e_name(visitor,jsoncons::bson::bson_container_type::array,ec);
+                        read_value(visitor, type, ec);
+                    }
+                    else
+                    {
+                        end_array(visitor,ec);
+                    }
+                    break;
+                }
+                case parse_mode::value:
+                    state_stack_.back().mode = parse_mode::document;
+                    read_value(visitor,state_stack_.back().type,ec);
+                    break;
+                case parse_mode::accept:
+                {
+                    JSONCONS_ASSERT(state_stack_.size() == 1);
+                    state_stack_.clear();
+                    more_ = false;
+                    done_ = true;
+                    visitor.flush();
+                    break;
+                }
+            }
+        }
+    }
+
+private:
+
+    void begin_document(json_visitor& visitor, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(static_cast<int>(state_stack_.size()) > options_.max_nesting_depth()))
+        {
+            ec = bson_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+
+        uint8_t buf[sizeof(int32_t)]; 
+        size_t n = source_.read(buf, sizeof(int32_t));
+        if (JSONCONS_UNLIKELY(n != sizeof(int32_t)))
+        {
+            ec = bson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+
+        auto length = binary::little_to_native<int32_t>(buf, sizeof(buf));
+
+        more_ = visitor.begin_object(semantic_tag::none, *this, ec);
+        state_stack_.emplace_back(parse_mode::document,length,n);
+    }
+
+    void end_document(json_visitor& visitor, std::error_code& ec)
+    {
+        JSONCONS_ASSERT(state_stack_.size() >= 2);
+
+        more_ = visitor.end_object(*this,ec);
+        if (JSONCONS_UNLIKELY(state_stack_.back().pos != state_stack_.back().length))
+        {
+            ec = bson_errc::size_mismatch;
+            more_ = false;
+            return;
+        }
+        std::size_t pos = state_stack_.back().pos;
+        state_stack_.pop_back();
+        state_stack_.back().pos += pos;
+    }
+
+    void begin_array(json_visitor& visitor, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(static_cast<int>(state_stack_.size()) > options_.max_nesting_depth()))
+        {
+            ec = bson_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+        uint8_t buf[sizeof(int32_t)]; 
+        std::size_t n = source_.read(buf, sizeof(int32_t));
+        if (JSONCONS_UNLIKELY(n != sizeof(int32_t)))
+        {
+            ec = bson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        auto length = binary::little_to_native<int32_t>(buf, sizeof(buf));
+
+        more_ = visitor.begin_array(semantic_tag::none, *this, ec);
+        if (ec)
+        {
+            return;
+        }
+        state_stack_.emplace_back(parse_mode::array, length, n);
+    }
+
+    void end_array(json_visitor& visitor, std::error_code& ec)
+    {
+        JSONCONS_ASSERT(state_stack_.size() >= 2);
+
+        more_ = visitor.end_array(*this, ec);
+        if (JSONCONS_UNLIKELY(state_stack_.back().pos != state_stack_.back().length))
+        {
+            ec = bson_errc::size_mismatch;
+            more_ = false;
+            return;
+        }
+        std::size_t pos = state_stack_.back().pos;
+        state_stack_.pop_back();
+        state_stack_.back().pos += pos;
+    }
+
+    void read_e_name(json_visitor& visitor, jsoncons::bson::bson_container_type type, std::error_code& ec)
+    {
+        text_buffer_.clear();
+        read_cstring(ec);
+        if (ec)
+        {
+            return;
+        }
+        if (type == jsoncons::bson::bson_container_type::document)
+        {
+            auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+            if (JSONCONS_UNLIKELY(result.ec != unicode_traits::conv_errc()))
+            {
+                ec = bson_errc::invalid_utf8_text_string;
+                more_ = false;
+                return;
+            }
+            more_ = visitor.key(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), *this, ec);
+        }
+    }
+
+    void read_value(json_visitor& visitor, uint8_t type, std::error_code& ec)
+    {
+        switch (type)
+        {
+            case jsoncons::bson::bson_type::double_type:
+            {
+                uint8_t buf[sizeof(double)]; 
+                std::size_t n = source_.read(buf, sizeof(double));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(double)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                double res = binary::little_to_native<double>(buf, sizeof(buf));
+                more_ = visitor.double_value(res, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::symbol_type:
+            case jsoncons::bson::bson_type::min_key_type:
+            case jsoncons::bson::bson_type::max_key_type:
+            case jsoncons::bson::bson_type::string_type:
+            {
+                text_buffer_.clear();
+                read_string(ec);
+                if (ec)
+                {
+                    return;
+                }
+                auto result = unicode_traits::validate(text_buffer_.data(), text_buffer_.size());
+                if (JSONCONS_UNLIKELY(result.ec != unicode_traits::conv_errc()))
+                {
+                    ec = bson_errc::invalid_utf8_text_string;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.string_value(text_buffer_, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::javascript_type:
+            {
+                text_buffer_.clear();
+                read_string(ec);
+                if (ec)
+                {
+                    return;
+                }
+                auto result = unicode_traits::validate(text_buffer_.data(), text_buffer_.size());
+                if (JSONCONS_UNLIKELY(result.ec != unicode_traits::conv_errc()))
+                {
+                    ec = bson_errc::invalid_utf8_text_string;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.string_value(text_buffer_, semantic_tag::code, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::regex_type:
+            {
+                text_buffer_.clear();
+                text_buffer_.push_back('/');
+                read_cstring(ec);
+                if (ec)
+                {
+                    return;
+                }
+                text_buffer_.push_back('/');
+                read_cstring(ec);
+                if (ec)
+                {
+                    return;
+                }
+                more_ = visitor.string_value(text_buffer_, semantic_tag::regex, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::document_type: 
+            {
+                begin_document(visitor,ec);
+                break;
+            }
+
+            case jsoncons::bson::bson_type::array_type: 
+            {
+                begin_array(visitor,ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::undefined_type: 
+                {
+                    more_ = visitor.null_value(semantic_tag::undefined, *this, ec);
+                    break;
+                }
+            case jsoncons::bson::bson_type::null_type: 
+            {
+                more_ = visitor.null_value(semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::bool_type:
+            {
+                uint8_t c;
+                std::size_t n = source_.read(&c, 1);
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != 1))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.bool_value(c != 0, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::int32_type: 
+            {
+                uint8_t buf[sizeof(int32_t)]; 
+                std::size_t n = source_.read(buf, sizeof(int32_t));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(int32_t)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                auto val = binary::little_to_native<int32_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+
+            case jsoncons::bson::bson_type::timestamp_type: 
+            {
+                uint8_t buf[sizeof(uint64_t)]; 
+                std::size_t n = source_.read(buf, sizeof(uint64_t));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(uint64_t)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                auto val = binary::little_to_native<uint64_t>(buf, sizeof(buf));
+                more_ = visitor.uint64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+
+            case jsoncons::bson::bson_type::int64_type: 
+            {
+                uint8_t buf[sizeof(int64_t)]; 
+                std::size_t n = source_.read(buf, sizeof(int64_t));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(int64_t)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                auto val = binary::little_to_native<int64_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+
+            case jsoncons::bson::bson_type::datetime_type: 
+            {
+                uint8_t buf[sizeof(int64_t)]; 
+                std::size_t n = source_.read(buf, sizeof(int64_t));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(int64_t)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                auto val = binary::little_to_native<int64_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::epoch_milli, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::binary_type: 
+            {
+                uint8_t buf[sizeof(int32_t)]; 
+                std::size_t n = source_.read(buf, sizeof(int32_t));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(int32_t)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                const auto len = binary::little_to_native<int32_t>(buf, sizeof(buf));
+                if (JSONCONS_UNLIKELY(len < 0))
+                {
+                    ec = bson_errc::length_is_negative;
+                    more_ = false;
+                    return;
+                }
+                uint8_t subtype;
+                n = source_.read(&subtype, 1);
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != 1))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                bytes_buffer_.clear();
+                n = source_reader<Source>::read(source_, bytes_buffer_, len);
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != static_cast<std::size_t>(len)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                more_ = visitor.byte_string_value(bytes_buffer_, 
+                                                  subtype, 
+                                                  *this,
+                                                  ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::decimal128_type: 
+            {
+                uint8_t buf[sizeof(uint64_t)*2]; 
+                std::size_t n = source_.read(buf, sizeof(buf));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(buf)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                decimal128_t dec;
+                dec.low = binary::little_to_native<uint64_t>(buf, sizeof(uint64_t));
+                dec.high = binary::little_to_native<uint64_t>(buf+sizeof(uint64_t), sizeof(uint64_t));
+
+                text_buffer_.clear();
+                text_buffer_.resize(bson::decimal128_limits::buf_size);
+                auto r = bson::decimal128_to_chars(&text_buffer_[0], &text_buffer_[0]+text_buffer_.size(), dec);
+                more_ = visitor.string_value(string_view(text_buffer_.data(),static_cast<std::size_t>(r.ptr-text_buffer_.data())), semantic_tag::float128, *this, ec);
+                break;
+            }
+            case jsoncons::bson::bson_type::object_id_type: 
+            {
+                uint8_t buf[12]; 
+                std::size_t n = source_.read(buf, sizeof(buf));
+                state_stack_.back().pos += n;
+                if (JSONCONS_UNLIKELY(n != sizeof(buf)))
+                {
+                    ec = bson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                oid_t oid(buf);
+                to_string(oid, text_buffer_);
+
+                more_ = visitor.string_value(text_buffer_, semantic_tag::id, *this, ec);
+                break;
+            }
+            default:
+            {
+                ec = bson_errc::unknown_type;
+                more_ = false;
+                return;
+            }
+        }
+    }
+
+    void read_cstring(std::error_code& ec)
+    {
+        uint8_t c = 0xff;
+        while (true)
+        {
+            std::size_t n = source_.read(&c, 1);
+            state_stack_.back().pos += n;
+            if (JSONCONS_UNLIKELY(n != 1))
+            {
+                ec = bson_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            if (c == 0)
+            {
+                break;
+            }
+            text_buffer_.push_back(c);
+        }
+    }
+
+    void read_string(std::error_code& ec)
+    {
+        uint8_t buf[sizeof(int32_t)]; 
+        std::size_t n = source_.read(buf, sizeof(int32_t));
+        state_stack_.back().pos += n;
+        if (JSONCONS_UNLIKELY(n != sizeof(int32_t)))
+        {
+            ec = bson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        auto len = binary::little_to_native<int32_t>(buf, sizeof(buf));
+        if (JSONCONS_UNLIKELY(len < 1))
+        {
+            ec = bson_errc::string_length_is_non_positive;
+            more_ = false;
+            return;
+        }
+
+        std::size_t size = static_cast<std::size_t>(len) - static_cast<std::size_t>(1);
+        n = source_reader<Source>::read(source_, text_buffer_, size);
+        state_stack_.back().pos += n;
+
+        if (JSONCONS_UNLIKELY(n != size))
+        {
+            ec = bson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        uint8_t c;
+        n = source_.read(&c, 1);
+        state_stack_.back().pos += n;
+        if (JSONCONS_UNLIKELY(n != 1))
+        {
+            ec = bson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+    }
+};
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_reader.hpp b/include/jsoncons_ext/bson/bson_reader.hpp
new file mode 100644
index 0000000..0079cc9
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_reader.hpp
@@ -0,0 +1,92 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_READER_HPP
+#define JSONCONS_BSON_BSON_READER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/bson/bson_type.hpp>
+#include <jsoncons_ext/bson/bson_error.hpp>
+#include <jsoncons_ext/bson/bson_parser.hpp>
+
+namespace jsoncons { namespace bson {
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_bson_reader 
+{
+    basic_bson_parser<Source,Allocator> parser_;
+    json_visitor& visitor_;
+public:
+    template <class Sourceable>
+    basic_bson_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const Allocator alloc)
+       : basic_bson_reader(std::forward<Sourceable>(source),
+                           visitor,
+                           bson_decode_options(),
+                           alloc)
+    {
+    }
+
+    template <class Sourceable>
+    basic_bson_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const bson_decode_options& options = bson_decode_options(),
+                      const Allocator alloc=Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         visitor_(visitor)
+    {
+    }
+
+    void read()
+    {
+        std::error_code ec;
+        read(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,line(),column()));
+        }
+    }
+
+    void read(std::error_code& ec)
+    {
+        parser_.reset();
+        parser_.parse(visitor_, ec);
+        if (ec)
+        {
+            return;
+        }
+    }
+
+    std::size_t line() const
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const
+    {
+        return parser_.column();
+    }
+};
+
+using bson_stream_reader = basic_bson_reader<jsoncons::binary_stream_source>;
+using bson_bytes_reader = basic_bson_reader<jsoncons::bytes_source>;
+
+#if !defined(JSONCONS_NO_DEPRECATED) 
+JSONCONS_DEPRECATED_MSG("Instead, use bson_stream_reader") typedef bson_stream_reader bson_reader;
+JSONCONS_DEPRECATED_MSG("Instead, use bson_bytes_reader") typedef bson_bytes_reader bson_buffer_reader;
+#endif
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/bson/bson_type.hpp b/include/jsoncons_ext/bson/bson_type.hpp
new file mode 100644
index 0000000..cf12344
--- /dev/null
+++ b/include/jsoncons_ext/bson/bson_type.hpp
@@ -0,0 +1,44 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_BSON_TYPE_HPP
+#define JSONCONS_BSON_BSON_TYPE_HPP
+
+#include <string>
+#include <memory>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace bson {
+
+    namespace bson_type
+    {
+        const uint8_t double_type = 0x01;
+        const uint8_t string_type = 0x02; // UTF-8 string
+        const uint8_t document_type = 0x03;
+        const uint8_t array_type = 0x04;
+        const uint8_t binary_type = 0x05;
+        const uint8_t undefined_type = 0x06; // map to null
+        const uint8_t object_id_type = 0x07;
+        const uint8_t bool_type = 0x08;
+        const uint8_t datetime_type = 0x09;
+        const uint8_t null_type = 0x0a;
+        const uint8_t regex_type = 0x0b;
+        const uint8_t javascript_type = 0x0d;
+        const uint8_t symbol_type = 0x0e; // deprecated, mapped to string
+        const uint8_t javascript_with_scope_type = 0x0f; // unsupported
+        const uint8_t int32_type = 0x10;
+        const uint8_t timestamp_type = 0x11; // MongoDB internal Timestamp, uint64
+        const uint8_t int64_type = 0x12;
+        const uint8_t decimal128_type = 0x13;
+        const uint8_t min_key_type = 0xff;
+        const uint8_t max_key_type = 0x7f;
+    }
+
+    enum class bson_container_type {document, array};
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/bson/decode_bson.hpp b/include/jsoncons_ext/bson/decode_bson.hpp
new file mode 100644
index 0000000..ad352f6
--- /dev/null
+++ b/include/jsoncons_ext/bson/decode_bson.hpp
@@ -0,0 +1,201 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_DECODE_BSON_HPP
+#define JSONCONS_BSON_DECODE_BSON_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/bson/bson_reader.hpp>
+#include <jsoncons_ext/bson/bson_cursor.hpp>
+
+namespace jsoncons { 
+namespace bson {
+
+    template<class T, class Source>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_bson(const Source& v, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_bson_reader<jsoncons::bytes_source> reader(v, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_bson(const Source& v, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        basic_bson_cursor<bytes_source> cursor(v, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_bson(std::istream& is, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        bson_stream_reader reader(is, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_bson(std::istream& is, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        basic_bson_cursor<binary_stream_source> cursor(is, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_bson(InputIt first, InputIt last,
+                const bson_decode_options& options = bson_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_bson_reader<binary_iterator_source<InputIt>> reader(binary_iterator_source<InputIt>(first, last), adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_bson(InputIt first, InputIt last,
+                const bson_decode_options& options = bson_decode_options())
+    {
+        basic_bson_cursor<binary_iterator_source<InputIt>> cursor(binary_iterator_source<InputIt>(first, last), options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    // With leading allocator parameter
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const Source& v, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_bson_reader<jsoncons::bytes_source,TempAllocator> reader(v, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const Source& v, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        basic_bson_cursor<bytes_source,TempAllocator> cursor(v, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                std::istream& is, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_bson_reader<jsoncons::binary_stream_source,TempAllocator> reader(is, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                std::istream& is, 
+                const bson_decode_options& options = bson_decode_options())
+    {
+        basic_bson_cursor<binary_stream_source,TempAllocator> cursor(is, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+  
+} // bson
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/bson/encode_bson.hpp b/include/jsoncons_ext/bson/encode_bson.hpp
new file mode 100644
index 0000000..55f8cf5
--- /dev/null
+++ b/include/jsoncons_ext/bson/encode_bson.hpp
@@ -0,0 +1,144 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_BSON_ENCODE_BSON_HPP
+#define JSONCONS_BSON_ENCODE_BSON_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/bson/bson_encoder.hpp>
+#include <jsoncons_ext/bson/bson_reader.hpp>
+
+namespace jsoncons { 
+namespace bson {
+
+    template<class T, class Container>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_bson(const T& j, 
+                Container& v, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_bson_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_bson(const T& val, 
+                Container& v, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        basic_bson_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_bson(const T& j, 
+                std::ostream& os, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        bson_stream_encoder encoder(os, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_bson(const T& val, 
+                std::ostream& os, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        bson_stream_encoder encoder(os, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+  
+    // with temp_allocator_rag
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& j, 
+                Container& v, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_bson_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& val, 
+                Container& v, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        basic_bson_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& j, 
+                std::ostream& os, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_bson_encoder<jsoncons::binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_bson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& val, 
+                std::ostream& os, 
+                const bson_encode_options& options = bson_encode_options())
+    {
+        basic_bson_encoder<jsoncons::binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+      
+} // bson
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/cbor/cbor.hpp b/include/jsoncons_ext/cbor/cbor.hpp
new file mode 100644
index 0000000..3f7329f
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor.hpp
@@ -0,0 +1,26 @@
+// Copyright 2017 Daniel Parkerstd
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+
+#ifndef JSONCONS_CBOR_CBOR_HPP
+#define JSONCONS_CBOR_CBOR_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/json_filter.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/cbor/cbor_reader.hpp>
+#include <jsoncons_ext/cbor/cbor_cursor.hpp>
+#include <jsoncons_ext/cbor/cbor_encoder.hpp>
+#include <jsoncons_ext/cbor/encode_cbor.hpp>
+#include <jsoncons_ext/cbor/decode_cbor.hpp>
+
+#endif
+
diff --git a/include/jsoncons_ext/cbor/cbor_cursor.hpp b/include/jsoncons_ext/cbor/cbor_cursor.hpp
new file mode 100644
index 0000000..af0d1a8
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_cursor.hpp
@@ -0,0 +1,351 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_CURSOR_HPP
+#define JSONCONS_CBOR_CBOR_CURSOR_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/staj_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons_ext/cbor/cbor_parser.hpp>
+
+namespace jsoncons { 
+namespace cbor {
+
+template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>>
+class basic_cbor_cursor : public basic_staj_cursor<char>, private virtual ser_context
+{
+public:
+    using source_type = Source;
+    using char_type = char;
+    using allocator_type = Allocator;
+private:
+    basic_cbor_parser<Source,Allocator> parser_;
+    basic_staj_visitor<char_type> cursor_visitor_;
+    basic_json_visitor2_to_visitor_adaptor<char_type,Allocator> cursor_handler_adaptor_;
+    bool eof_;
+
+    // Noncopyable and nonmoveable
+    basic_cbor_cursor(const basic_cbor_cursor&) = delete;
+    basic_cbor_cursor& operator=(const basic_cbor_cursor&) = delete;
+
+public:
+    using string_view_type = string_view;
+
+    template <class Sourceable>
+    basic_cbor_cursor(Sourceable&& source,
+                      const cbor_decode_options& options = cbor_decode_options(),
+                      const Allocator& alloc = Allocator())
+        : parser_(std::forward<Sourceable>(source), options, alloc), 
+          cursor_visitor_(accept_all), 
+          cursor_handler_adaptor_(cursor_visitor_, alloc),
+          eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    // Constructors that set parse error codes
+
+    template <class Sourceable>
+    basic_cbor_cursor(Sourceable&& source, 
+                      std::error_code& ec)
+        : basic_cbor_cursor(std::allocator_arg, Allocator(),
+                            std::forward<Sourceable>(source), 
+                            cbor_decode_options(), 
+                            ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_cbor_cursor(Sourceable&& source, 
+                      const cbor_decode_options& options,
+                      std::error_code& ec)
+        : basic_cbor_cursor(std::allocator_arg, Allocator(),
+                            std::forward<Sourceable>(source), 
+                            options, 
+                            ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_cbor_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                      Sourceable&& source,
+                      const cbor_decode_options& options,
+                      std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(accept_all),
+         cursor_handler_adaptor_(cursor_visitor_, alloc),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    void reset()
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    void reset(std::error_code& ec)
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source, std::error_code& ec)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    bool done() const override
+    {
+        return parser_.done();
+    }
+
+    bool is_typed_array() const
+    {
+        return cursor_visitor_.is_typed_array();
+    }
+
+    const staj_event& current() const override
+    {
+        return cursor_visitor_.event();
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor) override
+    {
+        std::error_code ec;
+        read_to(visitor, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor,
+                 std::error_code& ec) override
+    {
+        if (cursor_visitor_.dump(visitor, *this, ec))
+        {
+            read_next(visitor, ec);
+        }
+    }
+
+    void next() override
+    {
+        std::error_code ec;
+        next(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void next(std::error_code& ec) override
+    {
+        read_next(ec);
+    }
+
+    const ser_context& context() const override
+    {
+        return *this;
+    }
+
+    bool eof() const
+    {
+        return eof_;
+    }
+
+    std::size_t line() const override
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const override
+    {
+        return parser_.column();
+    }
+
+    friend
+    staj_filter_view operator|(basic_cbor_cursor& cursor, 
+                               std::function<bool(const staj_event&, const ser_context&)> pred)
+    {
+        return staj_filter_view(cursor, pred);
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_cbor_cursor(Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      const cbor_decode_options& options = cbor_decode_options(),
+                      const Allocator& alloc = Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(filter), 
+         cursor_handler_adaptor_(cursor_visitor_, alloc),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_cbor_cursor(Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      std::error_code& ec)
+        : basic_cbor_cursor(std::allocator_arg, Allocator(),
+                            std::forward<Sourceable>(source), filter, ec)
+    {
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_cbor_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                      Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), alloc), 
+         cursor_visitor_(filter),
+         cursor_handler_adaptor_(cursor_visitor_, alloc),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&)")
+    void read(basic_json_visitor<char_type>& visitor)
+    {
+        read_to(visitor);
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&, std::error_code&)")
+    void read(basic_json_visitor<char_type>& visitor,
+                 std::error_code& ec) 
+    {
+        read_to(visitor, ec);
+    }
+#endif
+private:
+    static bool accept_all(const staj_event&, const ser_context&) 
+    {
+        return true;
+    }
+
+    void read_next(std::error_code& ec)
+    {
+        if (cursor_visitor_.in_available())
+        {
+            cursor_visitor_.send_available(ec);
+        }
+        else
+        {
+            parser_.restart();
+            while (!parser_.stopped())
+            {
+                parser_.parse(cursor_handler_adaptor_, ec);
+                if (ec) return;
+            }
+        }
+    }
+
+    void read_next(basic_json_visitor<char_type>& visitor, std::error_code& ec)
+    {
+        {
+            struct resource_wrapper
+            {
+                basic_json_visitor2_to_visitor_adaptor<char_type,Allocator>& adaptor;
+                basic_json_visitor<char_type>& original;
+
+                resource_wrapper(basic_json_visitor2_to_visitor_adaptor<char_type,Allocator>& adaptor,
+                                 basic_json_visitor<char_type>& visitor)
+                    : adaptor(adaptor), original(adaptor.destination())
+                {
+                    adaptor.destination(visitor);
+                }
+
+                ~resource_wrapper()
+                {
+                    adaptor.destination(original);
+                }
+            } wrapper(cursor_handler_adaptor_, visitor);
+
+            parser_.restart();
+            while (!parser_.stopped())
+            {
+                parser_.parse(cursor_handler_adaptor_, ec);
+                if (ec)
+                {
+                    return;
+                }
+            }
+        }
+    }
+};
+
+using cbor_stream_cursor = basic_cbor_cursor<jsoncons::binary_stream_source>;
+using cbor_bytes_cursor = basic_cbor_cursor<jsoncons::bytes_source>;
+
+} // namespace cbor
+} // namespace jsoncons
+
+#endif
+
diff --git a/include/jsoncons_ext/cbor/cbor_cursor2.hpp b/include/jsoncons_ext/cbor/cbor_cursor2.hpp
new file mode 100644
index 0000000..eee7445
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_cursor2.hpp
@@ -0,0 +1,265 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_CURSOR2_HPP
+#define JSONCONS_CBOR_CBOR_CURSOR2_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor2.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/staj2_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons_ext/cbor/cbor_parser.hpp>
+
+namespace jsoncons { 
+namespace cbor {
+
+    template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>>
+    class basic_cbor_cursor2 : public basic_staj2_cursor<char>, private virtual ser_context
+    {
+    public:
+        using source_type = Source;
+        using char_type = char;
+        using allocator_type = Allocator;
+    private:
+        basic_cbor_parser<Source,Allocator> parser_;
+        basic_staj2_visitor<char_type> cursor_visitor_;
+        bool eof_;
+
+        // Noncopyable and nonmoveable
+        basic_cbor_cursor2(const basic_cbor_cursor2&) = delete;
+        basic_cbor_cursor2& operator=(const basic_cbor_cursor2&) = delete;
+
+    public:
+        using string_view_type = string_view;
+
+        template <class Sourceable>
+        basic_cbor_cursor2(Sourceable&& source,
+                          const cbor_decode_options& options = cbor_decode_options(),
+                          const Allocator& alloc = Allocator())
+            : parser_(std::forward<Sourceable>(source), options, alloc), 
+              cursor_visitor_(accept_all), 
+              eof_(false)
+        {
+            if (!done())
+            {
+                next();
+            }
+        }
+
+        // Constructors that set parse error codes
+
+        template <class Sourceable>
+        basic_cbor_cursor2(Sourceable&& source, 
+                          std::error_code& ec)
+            : basic_cbor_cursor2(std::allocator_arg, Allocator(),
+                                std::forward<Sourceable>(source), 
+                                cbor_decode_options(), 
+                                ec)
+        {
+        }
+
+        template <class Sourceable>
+        basic_cbor_cursor2(Sourceable&& source, 
+                          const cbor_decode_options& options,
+                          std::error_code& ec)
+            : basic_cbor_cursor2(std::allocator_arg, Allocator(),
+                                std::forward<Sourceable>(source), 
+                                options, 
+                                ec)
+        {
+        }
+
+        template <class Sourceable>
+        basic_cbor_cursor2(std::allocator_arg_t, const Allocator& alloc, 
+                          Sourceable&& source,
+                          const cbor_decode_options& options,
+                          std::error_code& ec)
+           : parser_(std::forward<Sourceable>(source), options, alloc), 
+             cursor_visitor_(accept_all),
+             eof_(false)
+        {
+            if (!done())
+            {
+                next(ec);
+            }
+        }
+
+        void reset()
+        {
+            parser_.reset();
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next();
+            }
+        }
+
+        template <class Sourceable>
+        void reset(Sourceable&& source)
+        {
+            parser_.reset(std::forward<Sourceable>(source));
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next();
+            }
+        }
+
+        void reset(std::error_code& ec)
+        {
+            parser_.reset();
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next(ec);
+            }
+        }
+
+        template <class Sourceable>
+        void reset(Sourceable&& source, std::error_code& ec)
+        {
+            parser_.reset(std::forward<Sourceable>(source));
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next(ec);
+            }
+        }
+
+        bool done() const override
+        {
+            return parser_.done();
+        }
+
+        bool is_typed_array() const
+        {
+            return cursor_visitor_.is_typed_array();
+        }
+
+        const staj2_event& current() const override
+        {
+            return cursor_visitor_.event();
+        }
+
+        void read_to(basic_json_visitor2<char_type>& visitor) override
+        {
+            std::error_code ec;
+            read_to(visitor, ec);
+            if (ec)
+            {
+                JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+            }
+        }
+
+        void read_to(basic_json_visitor2<char_type>& visitor,
+                     std::error_code& ec) override
+        {
+            if (cursor_visitor_.dump(visitor, *this, ec))
+            {
+                read_next(visitor, ec);
+            }
+        }
+
+        void next() override
+        {
+            std::error_code ec;
+            next(ec);
+            if (ec)
+            {
+                JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+            }
+        }
+
+        void next(std::error_code& ec) override
+        {
+            read_next(ec);
+        }
+
+        const ser_context& context() const override
+        {
+            return *this;
+        }
+
+        bool eof() const
+        {
+            return eof_;
+        }
+
+        std::size_t line() const override
+        {
+            return parser_.line();
+        }
+
+        std::size_t column() const override
+        {
+            return parser_.column();
+        }
+
+        friend
+        staj2_filter_view operator|(basic_cbor_cursor2& cursor, 
+                                   std::function<bool(const staj2_event&, const ser_context&)> pred)
+        {
+            return staj2_filter_view(cursor, pred);
+        }
+
+    private:
+        static bool accept_all(const staj2_event&, const ser_context&) 
+        {
+            return true;
+        }
+
+        void read_next(std::error_code& ec)
+        {
+            if (cursor_visitor_.in_available())
+            {
+                cursor_visitor_.send_available(ec);
+            }
+            else
+            {
+                parser_.restart();
+                while (!parser_.stopped())
+                {
+                    parser_.parse(cursor_visitor_, ec);
+                    if (ec) return;
+                }
+            }
+        }
+
+        void read_next(basic_json_visitor2<char_type>& visitor, std::error_code& ec)
+        {
+            parser_.restart();
+            while (!parser_.stopped())
+            {
+                parser_.parse(visitor, ec);
+                if (ec)
+                {
+                    return;
+                }
+            }
+        }
+    };
+
+    using cbor_stream_cursor2 = basic_cbor_cursor2<jsoncons::binary_stream_source>;
+    using cbor_bytes_cursor2 = basic_cbor_cursor2<jsoncons::bytes_source>;
+
+} // namespace cbor
+} // namespace jsoncons
+
+#endif
+
diff --git a/include/jsoncons_ext/cbor/cbor_detail.hpp b/include/jsoncons_ext/cbor/cbor_detail.hpp
new file mode 100644
index 0000000..9acfc3c
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_detail.hpp
@@ -0,0 +1,93 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_DETAIL_HPP
+#define JSONCONS_CBOR_CBOR_DETAIL_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <iterator> // std::forward_iterator_tag
+#include <limits> // std::numeric_limits
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+// 0x00..0x17 (0..23)
+#define JSONCONS_CBOR_0x00_0x17 \
+    0x00:case 0x01:case 0x02:case 0x03:case 0x04:case 0x05:case 0x06:case 0x07:case 0x08:case 0x09:case 0x0a:case 0x0b:case 0x0c:case 0x0d:case 0x0e:case 0x0f:case 0x10:case 0x11:case 0x12:case 0x13:case 0x14:case 0x15:case 0x16:case 0x17
+
+#define JSONCONS_CBOR_ARRAY_TAGS \
+    0x40:case 0x41:case 0x42:case 0x43:case 0x44:case 0x45:case 0x46:case 0x47:case 0x48:case 0x49:case 0x4a:case 0x4b:case 0x4c:case 0x4d:case 0x4e:case 0x4f:case 0x50:case 0x51:case 0x52:case 0x53:case 0x54:case 0x55:case 0x56:case 0x57    
+
+namespace jsoncons { namespace cbor { namespace detail {
+
+//const uint8_t cbor_array_tags_010_mask = 0b11100000;
+//const uint8_t cbor_array_tags_f_mask = 0b00010000;
+//const uint8_t cbor_array_tags_s_mask = 0b00001000;
+//const uint8_t cbor_array_tags_e_mask = 0b00000100;
+//const uint8_t cbor_array_tags_ll_mask = 0b00000011;
+
+const uint8_t cbor_array_tags_010_mask = 0xE0;
+const uint8_t cbor_array_tags_f_mask = 0x10;
+const uint8_t cbor_array_tags_s_mask = 0x08;
+const uint8_t cbor_array_tags_e_mask = 0x04;
+const uint8_t cbor_array_tags_ll_mask = 0x03;
+
+const uint8_t cbor_array_tags_010_shift = 5;
+const uint8_t cbor_array_tags_f_shift = 4;
+const uint8_t cbor_array_tags_s_shift = 3;
+const uint8_t cbor_array_tags_e_shift = 2;
+const uint8_t cbor_array_tags_ll_shift = 0;
+
+enum class cbor_major_type : uint8_t
+{
+    unsigned_integer = 0x00,
+    negative_integer = 0x01,
+    byte_string = 0x02,
+    text_string = 0x03,
+    array = 0x04,
+    map = 0x05,   
+    semantic_tag = 0x06,
+    simple = 0x7
+};
+
+namespace additional_info
+{
+    const uint8_t indefinite_length = 0x1f;
+}
+
+inline
+size_t min_length_for_stringref(uint64_t index)
+{
+    std::size_t n;
+    if (index <= 23)
+    {
+        n = 3;
+    }
+    else if (index <= 255)
+    {
+        n = 4;
+    }
+    else if (index <= 65535)
+    {
+        n = 5;
+    }
+    else if (index <= 4294967295)
+    {
+        n = 7;
+    }
+    else 
+    {
+        n = 11;
+    }
+    return n;
+}
+
+}}}
+
+#endif
diff --git a/include/jsoncons_ext/cbor/cbor_encoder.hpp b/include/jsoncons_ext/cbor/cbor_encoder.hpp
new file mode 100644
index 0000000..f4699ee
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_encoder.hpp
@@ -0,0 +1,1766 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_ENCODER_HPP
+#define JSONCONS_CBOR_CBOR_ENCODER_HPP
+
+#include <string>
+#include <vector>
+#include <limits> // std::numeric_limits
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json_exception.hpp> // jsoncons::ser_error
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/sink.hpp>
+#include <jsoncons/detail/parse_number.hpp>
+#include <jsoncons_ext/cbor/cbor_error.hpp>
+#include <jsoncons_ext/cbor/cbor_options.hpp>
+
+namespace jsoncons { namespace cbor {
+
+enum class cbor_container_type {object, indefinite_length_object, array, indefinite_length_array};
+
+template<class Sink=jsoncons::binary_stream_sink,class Allocator=std::allocator<char>>
+class basic_cbor_encoder final : public basic_json_visitor<char>
+{
+    using super_type = basic_json_visitor<char>;
+
+    enum class decimal_parse_state { start, integer, exp1, exp2, fraction1 };
+    enum class hexfloat_parse_state { start, expect_0, expect_x, integer, exp1, exp2, fraction1 };
+
+    static constexpr int64_t nanos_in_second = 1000000000;
+    static constexpr int64_t millis_in_second = 1000;
+
+public:
+    using allocator_type = Allocator;
+    using sink_type = Sink;
+    using typename super_type::char_type;
+    using typename super_type::string_view_type;
+
+private:
+    using char_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<char_type>;
+    using byte_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<uint8_t>;                  
+
+    using string_type = std::basic_string<char_type,std::char_traits<char_type>,char_allocator_type>;
+    using byte_string_type = basic_byte_string<byte_allocator_type>;
+
+    struct stack_item
+    {
+        cbor_container_type type_;
+        std::size_t length_;
+        std::size_t count_;
+
+        stack_item(cbor_container_type type, std::size_t length = 0) noexcept
+           : type_(type), length_(length), count_(0)
+        {
+        }
+
+        std::size_t length() const
+        {
+            return length_;
+        }
+
+        std::size_t count() const
+        {
+            return count_;
+        }
+
+        bool is_object() const
+        {
+            return type_ == cbor_container_type::object || type_ == cbor_container_type::indefinite_length_object;
+        }
+
+        bool is_indefinite_length() const
+        {
+            return type_ == cbor_container_type::indefinite_length_array || type_ == cbor_container_type::indefinite_length_object;
+        }
+
+    };
+
+    typedef typename std::allocator_traits<allocator_type>:: template rebind_alloc<std::pair<const string_type,size_t>> string_size_allocator_type;
+    typedef typename std::allocator_traits<allocator_type>:: template rebind_alloc<std::pair<const byte_string_type,size_t>> byte_string_size_allocator_type;
+    typedef typename std::allocator_traits<allocator_type>:: template rebind_alloc<stack_item> stack_item_allocator_type;
+
+    Sink sink_;
+    const cbor_encode_options options_;
+    allocator_type alloc_;
+
+    std::vector<stack_item,stack_item_allocator_type> stack_;
+    std::map<string_type,size_t,std::less<string_type>,string_size_allocator_type> stringref_map_;
+    std::map<byte_string_type,size_t,std::less<byte_string_type>,byte_string_size_allocator_type> bytestringref_map_;
+    std::size_t next_stringref_ = 0;
+    int nesting_depth_;
+
+    // Noncopyable and nonmoveable
+    basic_cbor_encoder(const basic_cbor_encoder&) = delete;
+    basic_cbor_encoder& operator=(const basic_cbor_encoder&) = delete;
+public:
+    explicit basic_cbor_encoder(Sink&& sink, 
+                                const Allocator& alloc = Allocator())
+       : basic_cbor_encoder(std::forward<Sink>(sink), cbor_encode_options(), alloc)
+    {
+    }
+    basic_cbor_encoder(Sink&& sink, 
+                       const cbor_encode_options& options, 
+                       const Allocator& alloc = Allocator())
+       : sink_(std::forward<Sink>(sink)), 
+         options_(options), 
+         alloc_(alloc),
+         stack_(alloc),
+#if !defined(JSONCONS_NO_MAP_CONS_TAKES_ALLOCATOR) 
+         stringref_map_(alloc),
+         bytestringref_map_(alloc),
+#endif 
+         nesting_depth_(0)        
+    {
+        if (options.pack_strings())
+        {
+            write_tag(256);
+        }
+    }
+
+    ~basic_cbor_encoder() noexcept
+    {
+        JSONCONS_TRY
+        {
+            sink_.flush();
+        }
+        JSONCONS_CATCH(...)
+        {
+        }
+    }
+
+    void reset()
+    {
+        stack_.clear();
+        stringref_map_.clear();
+        bytestringref_map_.clear();
+        next_stringref_ = 0;
+        nesting_depth_ = 0;
+    }
+
+    void reset(Sink&& sink)
+    {
+        sink_ = std::move(sink);
+        reset();
+    }
+
+private:
+    // Implementing methods
+
+    void visit_flush() override
+    {
+        sink_.flush();
+    }
+
+    bool visit_begin_object(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = cbor_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(cbor_container_type::indefinite_length_object);
+        
+        sink_.push_back(0xbf);
+        return true;
+    }
+
+    bool visit_begin_object(std::size_t length, semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = cbor_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(cbor_container_type::object, length);
+
+        if (length <= 0x17)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xa0 + length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xb8), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint8_t>(length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xb9), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint16_t>(length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xba), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint32_t>(length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xffffffffffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xbb), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint64_t>(length), 
+                                  std::back_inserter(sink_));
+        }
+
+        return true;
+    }
+
+    bool visit_end_object(const ser_context&, std::error_code& ec) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        --nesting_depth_;
+
+        if (stack_.back().is_indefinite_length())
+        {
+            sink_.push_back(0xff);
+        }
+        else
+        {
+            if (stack_.back().count() < stack_.back().length())
+            {
+                ec = cbor_errc::too_few_items;
+                return false;
+            }
+            if (stack_.back().count() > stack_.back().length())
+            {
+                ec = cbor_errc::too_many_items;
+                return false;
+            }
+        }
+
+        stack_.pop_back();
+        end_value();
+
+        return true;
+    }
+
+    bool visit_begin_array(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = cbor_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(cbor_container_type::indefinite_length_array);
+        sink_.push_back(0x9f);
+        return true;
+    }
+
+    bool visit_begin_array(std::size_t length, semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = cbor_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(cbor_container_type::array, length);
+        if (length <= 0x17)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x80 + length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x98), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint8_t>(length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x99), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint16_t>(length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x9a), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint32_t>(length), 
+                                  std::back_inserter(sink_));
+        } 
+        else if (length <= 0xffffffffffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x9b), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint64_t>(length), 
+                                  std::back_inserter(sink_));
+        }
+        return true;
+    }
+
+    bool visit_end_array(const ser_context&, std::error_code& ec) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        --nesting_depth_;
+
+        if (stack_.back().is_indefinite_length())
+        {
+            sink_.push_back(0xff);
+        }
+        else
+        {
+            if (stack_.back().count() < stack_.back().length())
+            {
+                ec = cbor_errc::too_few_items;
+                return false;
+            }
+            if (stack_.back().count() > stack_.back().length())
+            {
+                ec = cbor_errc::too_many_items;
+                return false;
+            }
+        }
+
+        stack_.pop_back();
+        end_value();
+
+        return true;
+    }
+
+    bool visit_key(const string_view_type& name, const ser_context&, std::error_code&) override
+    {
+        write_string(name);
+        return true;
+    }
+
+    bool visit_null(semantic_tag tag, const ser_context&, std::error_code&) override
+    {
+        if (tag == semantic_tag::undefined)
+        {
+            sink_.push_back(0xf7);
+        }
+        else
+        {
+            sink_.push_back(0xf6);
+        }
+
+        end_value();
+        return true;
+    }
+
+    void write_string(const string_view& sv)
+    {
+        auto sink = unicode_traits::validate(sv.data(), sv.size());
+        if (sink.ec != unicode_traits::conv_errc())
+        {
+            JSONCONS_THROW(ser_error(cbor_errc::invalid_utf8_text_string));
+        }
+
+        if (options_.pack_strings() && sv.size() >= jsoncons::cbor::detail::min_length_for_stringref(next_stringref_))
+        {
+            string_type s(sv.data(), sv.size(), alloc_);
+            auto it = stringref_map_.find(s);
+            if (it == stringref_map_.end())
+            {
+                stringref_map_.emplace(std::make_pair(std::move(s), next_stringref_++));
+                write_utf8_string(sv);
+            }
+            else
+            {
+                write_tag(25);
+                write_uint64_value(it->second);
+            }
+        }
+        else
+        {
+            write_utf8_string(sv);
+        }
+    }
+
+    void write_utf8_string(const string_view& sv)
+    {
+        const size_t length = sv.size();
+
+        if (length <= 0x17)
+        {
+            // fixstr stores a byte array whose length is upto 31 bytes
+            binary::native_to_big(static_cast<uint8_t>(0x60 + length), 
+                                            std::back_inserter(sink_));
+        }
+        else if (length <= 0xff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x78), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint8_t>(length), 
+                                            std::back_inserter(sink_));
+        }
+        else if (length <= 0xffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x79), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint16_t>(length), 
+                                            std::back_inserter(sink_));
+        }
+        else if (length <= 0xffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x7a), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint32_t>(length), 
+                                            std::back_inserter(sink_));
+        }
+        else if (length <= 0xffffffffffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x7b), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint64_t>(length), 
+                                            std::back_inserter(sink_));
+        }
+
+        for (auto c : sv)
+        {
+            sink_.push_back(c);
+        }
+    }
+
+    void write_bignum(bigint& n)
+    {
+        bool is_neg = n < 0;
+        if (is_neg)
+        {
+            n = - n -1;
+        }
+
+        int signum;
+        std::vector<uint8_t> data;
+        n.write_bytes_be(signum, data);
+        std::size_t length = data.size();
+
+        if (is_neg)
+        {
+            write_tag(3);
+        }
+        else
+        {
+            write_tag(2);
+        }
+
+        if (length <= 0x17)
+        {
+            // fixstr stores a byte array whose length is upto 31 bytes
+            binary::native_to_big(static_cast<uint8_t>(0x40 + length), 
+                                  std::back_inserter(sink_));
+        }
+        else if (length <= 0xff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x58), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint8_t>(length), 
+                                  std::back_inserter(sink_));
+        }
+        else if (length <= 0xffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x59), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint16_t>(length), 
+                                  std::back_inserter(sink_));
+        }
+        else if (length <= 0xffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x5a), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint32_t>(length), 
+                                  std::back_inserter(sink_));
+        }
+        else if (length <= 0xffffffffffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x5b), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint64_t>(length), 
+                                  std::back_inserter(sink_));
+        }
+
+        for (auto c : data)
+        {
+            sink_.push_back(c);
+        }
+    }
+
+    bool write_decimal_value(const string_view_type& sv, const ser_context& context, std::error_code& ec)
+    {
+        bool more = true;
+
+        decimal_parse_state state = decimal_parse_state::start;
+        std::basic_string<char> s;
+        std::basic_string<char> exponent;
+        int64_t scale = 0;
+        for (auto c : sv)
+        {
+            switch (state)
+            {
+                case decimal_parse_state::start:
+                {
+                    switch (c)
+                    {
+                        case '-':
+                            s.push_back(c);
+                            state = decimal_parse_state::integer;
+                            break;
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            s.push_back(c);
+                            state = decimal_parse_state::integer;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_decimal_fraction;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case decimal_parse_state::integer:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            s.push_back(c);
+                            break;
+                        case 'e': case 'E':
+                            state = decimal_parse_state::exp1;
+                            break;
+                        case '.':
+                            state = decimal_parse_state::fraction1;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_decimal_fraction;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case decimal_parse_state::exp1:
+                {
+                    switch (c)
+                    {
+                        case '+':
+                            state = decimal_parse_state::exp2;
+                            break;
+                        case '-':
+                            exponent.push_back(c);
+                            state = decimal_parse_state::exp2;
+                            break;
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            exponent.push_back(c);
+                            state = decimal_parse_state::exp2;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_decimal_fraction;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case decimal_parse_state::exp2:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            exponent.push_back(c);
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_decimal_fraction;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case decimal_parse_state::fraction1:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            s.push_back(c);
+                            --scale;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_decimal_fraction;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+            }
+        }
+
+        write_tag(4);
+        more = visit_begin_array((std::size_t)2, semantic_tag::none, context, ec);
+        if (!more) {return more;}
+        if (exponent.length() > 0)
+        {
+            int64_t val;
+            auto r = jsoncons::detail::to_integer(exponent.data(), exponent.length(), val);
+            if (!r)
+            {
+                ec = r.error_code();
+                return false;
+            }
+            scale += val;
+        }
+        more = visit_int64(scale, semantic_tag::none, context, ec);
+        if (!more) {return more;}
+
+        int64_t val{ 0 };
+        auto r = jsoncons::detail::to_integer(s.data(),s.length(), val);
+        if (r)
+        {
+            more = visit_int64(val, semantic_tag::none, context, ec);
+            if (!more) {return more;}
+        }
+        else if (r.error_code() == jsoncons::detail::to_integer_errc::overflow)
+        {
+            bigint n = bigint::from_string(s.data(), s.length());
+            write_bignum(n);
+            end_value();
+        }
+        else
+        {
+            ec = r.error_code();
+            return false;
+        }
+        more = visit_end_array(context, ec);
+
+        return more;
+    }
+
+    bool write_hexfloat_value(const string_view_type& sv, const ser_context& context, std::error_code& ec)
+    {
+        bool more = true;
+
+        hexfloat_parse_state state = hexfloat_parse_state::start;
+        std::basic_string<char> s;
+        std::basic_string<char> exponent;
+        int64_t scale = 0;
+
+        for (auto c : sv)
+        {
+            switch (state)
+            {
+                case hexfloat_parse_state::start:
+                {
+                    switch (c)
+                    {
+                        case '-':
+                            s.push_back(c);
+                            state = hexfloat_parse_state::expect_0;
+                            break;
+                        case '0':
+                            state = hexfloat_parse_state::expect_x;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case hexfloat_parse_state::expect_0:
+                {
+                    switch (c)
+                    {
+                        case '0':
+                            state = hexfloat_parse_state::expect_x;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case hexfloat_parse_state::expect_x:
+                {
+                    switch (c)
+                    {
+                        case 'x':
+                        case 'X':
+                            state = hexfloat_parse_state::integer;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case hexfloat_parse_state::integer:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                            s.push_back(c);
+                            break;
+                        case 'p': case 'P':
+                            state = hexfloat_parse_state::exp1;
+                            break;
+                        case '.':
+                            state = hexfloat_parse_state::fraction1;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case hexfloat_parse_state::exp1:
+                {
+                    switch (c)
+                    {
+                        case '+':
+                            state = hexfloat_parse_state::exp2;
+                            break;
+                        case '-':
+                            exponent.push_back(c);
+                            state = hexfloat_parse_state::exp2;
+                            break;
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                            exponent.push_back(c);
+                            state = hexfloat_parse_state::exp2;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case hexfloat_parse_state::exp2:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                            exponent.push_back(c);
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+                case hexfloat_parse_state::fraction1:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                            s.push_back(c);
+                            scale -= 4;
+                            break;
+                        default:
+                        {
+                            ec = cbor_errc::invalid_bigfloat;
+                            return false;
+                        }
+                    }
+                    break;
+                }
+            }
+        }
+
+        write_tag(5);
+        more = visit_begin_array((std::size_t)2, semantic_tag::none, context, ec);
+        if (!more) return more;
+
+        if (exponent.length() > 0)
+        {
+            int64_t val{ 0 };
+            auto r = jsoncons::detail::base16_to_integer(exponent.data(), exponent.length(), val);
+            if (!r)
+            {
+                ec = r.error_code();
+                return false;
+            }
+            scale += val;
+        }
+        more = visit_int64(scale, semantic_tag::none, context, ec);
+        if (!more) return more;
+
+        int64_t val{ 0 };
+        auto r = jsoncons::detail::base16_to_integer(s.data(),s.length(), val);
+        if (r)
+        {
+            more = visit_int64(val, semantic_tag::none, context, ec);
+            if (!more) return more;
+        }
+        else if (r.error_code() == jsoncons::detail::to_integer_errc::overflow)
+        {
+            bigint n = bigint::from_string_radix(s.data(), s.length(), 16);
+            write_bignum(n);
+            end_value();
+        }
+        else
+        {
+            JSONCONS_THROW(json_runtime_error<std::invalid_argument>(r.error_code().message()));
+        }
+        return visit_end_array(context, ec);
+    }
+
+    bool visit_string(const string_view_type& sv, semantic_tag tag, const ser_context& context, std::error_code& ec) override
+    {
+        switch (tag)
+        {
+            case semantic_tag::bigint:
+            {
+                bigint n = bigint::from_string(sv.data(), sv.length());
+                write_bignum(n);
+                end_value();
+                break;
+            }
+            case semantic_tag::bigdec:
+            {
+                return write_decimal_value(sv, context, ec);
+            }
+            case semantic_tag::bigfloat:
+            {
+                return write_hexfloat_value(sv, context, ec);
+            }
+            case semantic_tag::datetime:
+            {
+                write_tag(0);
+
+                write_string(sv);
+                end_value();
+                break;
+            }
+            case semantic_tag::uri:
+            {
+                write_tag(32);
+                write_string(sv);
+                end_value();
+                break;
+            }
+            case semantic_tag::base64url:
+            {
+                write_tag(33);
+                write_string(sv);
+                end_value();
+                break;
+            }
+            case semantic_tag::base64:
+            {
+                write_tag(34);
+                write_string(sv);
+                end_value();
+                break;
+            }
+            default:
+            {
+                write_string(sv);
+                end_value();
+                break;
+            }
+        }
+        return true;
+    }
+
+    bool visit_byte_string(const byte_string_view& b, 
+                           semantic_tag tag, 
+                           const ser_context&,
+                           std::error_code&) override
+    {
+        byte_string_chars_format encoding_hint;
+        switch (tag)
+        {
+            case semantic_tag::base16:
+                encoding_hint = byte_string_chars_format::base16;
+                break;
+            case semantic_tag::base64:
+                encoding_hint = byte_string_chars_format::base64;
+                break;
+            case semantic_tag::base64url:
+                encoding_hint = byte_string_chars_format::base64url;
+                break;
+            default:
+                encoding_hint = byte_string_chars_format::none;
+                break;
+        }
+        switch (encoding_hint)
+        {
+            case byte_string_chars_format::base64url:
+                write_tag(21);
+                break;
+            case byte_string_chars_format::base64:
+                write_tag(22);
+                break;
+            case byte_string_chars_format::base16:
+                write_tag(23);
+                break;
+            default:
+                break;
+        }
+        if (options_.pack_strings() && b.size() >= jsoncons::cbor::detail::min_length_for_stringref(next_stringref_))
+        {
+            byte_string_type bs(b.data(), b.size(), alloc_);
+            auto it = bytestringref_map_.find(bs);
+            if (it == bytestringref_map_.end())
+            {
+                bytestringref_map_.emplace(std::make_pair(bs, next_stringref_++));
+                write_byte_string_value(bs);
+            }
+            else
+            {
+                write_tag(25);
+                write_uint64_value(it->second);
+            }
+        }
+        else
+        {
+            write_byte_string_value(b);
+        }
+
+        end_value();
+        return true;
+    }
+
+    bool visit_byte_string(const byte_string_view& b, 
+                           uint64_t ext_tag, 
+                           const ser_context&,
+                           std::error_code&) override
+    {
+        if (options_.pack_strings() && b.size() >= jsoncons::cbor::detail::min_length_for_stringref(next_stringref_))
+        {
+            byte_string_type bs(b.data(), b.size(), alloc_);
+            auto it = bytestringref_map_.find(bs);
+            if (it == bytestringref_map_.end())
+            {
+                bytestringref_map_.emplace(std::make_pair(bs, next_stringref_++));
+                write_tag(ext_tag);
+                write_byte_string_value(bs);
+            }
+            else
+            {
+                write_tag(25);
+                write_uint64_value(it->second);
+            }
+        }
+        else
+        {
+            write_tag(ext_tag);
+            write_byte_string_value(b);
+        }
+
+        end_value();
+        return true;
+    }
+
+    void write_byte_string_value(const byte_string_view& b) 
+    {
+        if (b.size() <= 0x17)
+        {
+            // fixstr stores a byte array whose length is upto 31 bytes
+            binary::native_to_big(static_cast<uint8_t>(0x40 + b.size()), 
+                                            std::back_inserter(sink_));
+        }
+        else if (b.size() <= 0xff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x58), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint8_t>(b.size()), 
+                                            std::back_inserter(sink_));
+        }
+        else if (b.size() <= 0xffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x59), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint16_t>(b.size()), 
+                                            std::back_inserter(sink_));
+        }
+        else if (b.size() <= 0xffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x5a), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint32_t>(b.size()), 
+                                            std::back_inserter(sink_));
+        }
+        else // if (b.size() <= 0xffffffffffffffff)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0x5b), 
+                                            std::back_inserter(sink_));
+            binary::native_to_big(static_cast<uint64_t>(b.size()), 
+                                            std::back_inserter(sink_));
+        }
+
+        for (auto c : b)
+        {
+            sink_.push_back(c);
+        }
+    }
+
+    bool visit_double(double val, 
+                      semantic_tag tag,
+                      const ser_context&,
+                      std::error_code&) override
+    {
+        switch (tag)
+        {
+            case semantic_tag::epoch_second:
+                write_tag(1);
+                break;
+            case semantic_tag::epoch_milli:
+                write_tag(1);
+                if (val != 0)
+                {
+                    val /= millis_in_second;
+                }
+                break;
+            case semantic_tag::epoch_nano:
+                write_tag(1);
+                if (val != 0)
+                {
+                    val /= nanos_in_second;
+                }
+                break;
+            default:
+                break;
+        }
+
+        float valf = (float)val;
+        if ((double)valf == val)
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xfa), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(valf, std::back_inserter(sink_));
+        }
+        else
+        {
+            binary::native_to_big(static_cast<uint8_t>(0xfb), 
+                                  std::back_inserter(sink_));
+            binary::native_to_big(val, std::back_inserter(sink_));
+        }
+
+        // write double
+
+        end_value();
+        return true;
+    }
+
+    bool visit_int64(int64_t value, 
+                        semantic_tag tag, 
+                        const ser_context& context,
+                        std::error_code& ec) override
+    {
+        switch (tag)
+        {
+            case semantic_tag::epoch_milli:
+            case semantic_tag::epoch_nano:
+                return visit_double(static_cast<double>(value), tag, context, ec);
+            case semantic_tag::epoch_second:
+                write_tag(1);
+                break;
+            default:
+                break;
+        }
+        if (value >= 0)
+        {
+            if (value <= 0x17)
+            {
+                binary::native_to_big(static_cast<uint8_t>(value), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (value <= (std::numeric_limits<uint8_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x18), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint8_t>(value), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (value <= (std::numeric_limits<uint16_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x19), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint16_t>(value), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (value <= (std::numeric_limits<uint32_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x1a), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint32_t>(value), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (value <= (std::numeric_limits<int64_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x1b), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<int64_t>(value), 
+                                  std::back_inserter(sink_));
+            }
+        } else
+        {
+            const auto posnum = -1 - value;
+            if (value >= -24)
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x20 + posnum), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (posnum <= (std::numeric_limits<uint8_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x38), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint8_t>(posnum), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (posnum <= (std::numeric_limits<uint16_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x39), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint16_t>(posnum), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (posnum <= (std::numeric_limits<uint32_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x3a), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint32_t>(posnum), 
+                                  std::back_inserter(sink_));
+            } 
+            else if (posnum <= (std::numeric_limits<int64_t>::max)())
+            {
+                binary::native_to_big(static_cast<uint8_t>(0x3b), 
+                                  std::back_inserter(sink_));
+                binary::native_to_big(static_cast<int64_t>(posnum), 
+                                  std::back_inserter(sink_));
+            }
+        }
+        end_value();
+        return true;
+    }
+
+    bool visit_uint64(uint64_t value, 
+                      semantic_tag tag, 
+                      const ser_context& context,
+                      std::error_code& ec) override
+    {
+        switch (tag)
+        {
+            case semantic_tag::epoch_milli:
+            case semantic_tag::epoch_nano:
+                return visit_double(static_cast<double>(value), tag, context, ec);
+            case semantic_tag::epoch_second:
+                write_tag(1);
+                break;
+            default:
+                break;
+        }
+
+        write_uint64_value(value);
+        end_value();
+        return true;
+    }
+
+    void write_tag(uint64_t value)
+    {
+        if (value <= 0x17)
+        {
+            sink_.push_back(0xc0 | static_cast<uint8_t>(value)); 
+        } 
+        else if (value <=(std::numeric_limits<uint8_t>::max)())
+        {
+            sink_.push_back(0xd8);
+            sink_.push_back(static_cast<uint8_t>(value));
+        } 
+        else if (value <=(std::numeric_limits<uint16_t>::max)())
+        {
+            sink_.push_back(0xd9);
+            binary::native_to_big(static_cast<uint16_t>(value), 
+                                            std::back_inserter(sink_));
+        }
+        else if (value <=(std::numeric_limits<uint32_t>::max)())
+        {
+            sink_.push_back(0xda);
+            binary::native_to_big(static_cast<uint32_t>(value), 
+                                            std::back_inserter(sink_));
+        }
+        else 
+        {
+            sink_.push_back(0xdb);
+            binary::native_to_big(static_cast<uint64_t>(value), 
+                                            std::back_inserter(sink_));
+        }
+    }
+
+    void write_uint64_value(uint64_t value) 
+    {
+        if (value <= 0x17)
+        {
+            sink_.push_back(static_cast<uint8_t>(value));
+        } 
+        else if (value <=(std::numeric_limits<uint8_t>::max)())
+        {
+            sink_.push_back(static_cast<uint8_t>(0x18));
+            sink_.push_back(static_cast<uint8_t>(value));
+        } 
+        else if (value <=(std::numeric_limits<uint16_t>::max)())
+        {
+            sink_.push_back(static_cast<uint8_t>(0x19));
+            binary::native_to_big(static_cast<uint16_t>(value), 
+                                            std::back_inserter(sink_));
+        } 
+        else if (value <=(std::numeric_limits<uint32_t>::max)())
+        {
+            sink_.push_back(static_cast<uint8_t>(0x1a));
+            binary::native_to_big(static_cast<uint32_t>(value), 
+                                            std::back_inserter(sink_));
+        } 
+        else if (value <=(std::numeric_limits<uint64_t>::max)())
+        {
+            sink_.push_back(static_cast<uint8_t>(0x1b));
+            binary::native_to_big(static_cast<uint64_t>(value), 
+                                            std::back_inserter(sink_));
+        }
+    }
+
+    bool visit_bool(bool value, semantic_tag, const ser_context&, std::error_code&) override
+    {
+        if (value)
+        {
+            sink_.push_back(0xf5);
+        }
+        else
+        {
+            sink_.push_back(0xf4);
+        }
+
+        end_value();
+        return true;
+    }
+
+    bool visit_typed_array(const jsoncons::span<const uint8_t>& v, 
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            switch (tag)
+            {
+                case semantic_tag::clamped:
+                    write_tag(0x44);
+                    break;
+                default:
+                    write_tag(0x40);
+                    break;
+            }
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(v.size(), semantic_tag::none, context, ec);
+            for (auto p = v.begin(); more && p != v.end(); ++p)
+            {
+                more = this->uint64_value(*p, tag, context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const uint16_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  uint16_t(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(uint16_t));
+            std::memcpy(v.data(),data.data(),data.size()*sizeof(uint16_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none, context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->uint64_value(*p, tag, context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const uint32_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  uint32_t(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(uint32_t));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(uint32_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none, context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->uint64_value(*p, semantic_tag::none, context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const uint64_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  uint64_t(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(uint64_t));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(uint64_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none, context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->uint64_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const int8_t>& data,  
+                        semantic_tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_tag(0x48);
+            std::vector<uint8_t> v(data.size()*sizeof(int8_t));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(int8_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none,context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->int64_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const int16_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  int16_t(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(int16_t));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(int16_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none,context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->int64_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const int32_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  int32_t(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(int32_t));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(int32_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none,context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->int64_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const int64_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  int64_t(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(int64_t));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(int64_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none,context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->int64_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(half_arg_t, const jsoncons::span<const uint16_t>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  half_arg, 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(uint16_t));
+            std::memcpy(v.data(),data.data(),data.size()*sizeof(uint16_t));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none, context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->half_value(*p, tag, context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const float>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  float(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(float));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(float));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none,context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->double_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+
+    bool visit_typed_array(const jsoncons::span<const double>& data,  
+                        semantic_tag tag,
+                        const ser_context& context, 
+                        std::error_code& ec) override
+    {
+        if (options_.use_typed_arrays())
+        {
+            write_typed_array_tag(std::integral_constant<bool, jsoncons::endian::native == jsoncons::endian::big>(), 
+                                  double(), 
+                                  tag);
+            std::vector<uint8_t> v(data.size()*sizeof(double));
+            std::memcpy(v.data(), data.data(), data.size()*sizeof(double));
+            write_byte_string_value(byte_string_view(v));
+            return true;
+        }
+        else
+        {
+            bool more = this->begin_array(data.size(), semantic_tag::none,context, ec);
+            for (auto p = data.begin(); more && p != data.end(); ++p)
+            {
+                more = this->double_value(*p,semantic_tag::none,context, ec);
+            }
+            if (more)
+            {
+                more = this->end_array(context, ec);
+            }
+            return more;
+        }
+    }
+/*
+    bool visit_typed_array(const jsoncons::span<const float128_type>&, 
+                        semantic_tag,
+                        const ser_context&, 
+                        std::error_code&) override
+    {
+        return true;
+    }
+*/
+    bool visit_begin_multi_dim(const jsoncons::span<const size_t>& shape,
+                            semantic_tag tag,
+                            const ser_context& context, 
+                            std::error_code& ec) override
+    {
+        switch (tag)
+        {
+            case semantic_tag::multi_dim_column_major:
+                write_tag(1040);
+                break;
+            default:
+                write_tag(40);
+                break;
+        }
+        bool more = visit_begin_array(2, semantic_tag::none, context, ec);
+        if (more)
+            more = visit_begin_array(shape.size(), semantic_tag::none, context, ec);
+        for (auto it = shape.begin(); more && it != shape.end(); ++it)
+        {
+            more = visit_uint64(*it, semantic_tag::none, context, ec);
+        }
+        if (more)
+        {
+            more = visit_end_array(context, ec);
+        }
+        return more;
+    }
+
+    bool visit_end_multi_dim(const ser_context& context,
+                          std::error_code& ec) override
+    {
+        bool more = visit_end_array(context, ec);
+        return more;
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               uint16_t,
+                               semantic_tag)
+    {
+        write_tag(0x41); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               uint16_t,
+                               semantic_tag)
+    {
+        write_tag(0x45);
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               uint32_t,
+                               semantic_tag)
+    {
+        write_tag(0x42); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               uint32_t,
+                               semantic_tag)
+    {
+        write_tag(0x46);  // little endian
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               uint64_t,
+                               semantic_tag)
+    {
+        write_tag(0x43); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               uint64_t,
+                               semantic_tag)
+    {
+        write_tag(0x47);  // little endian
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               int16_t,
+                               semantic_tag)
+    {
+        write_tag(0x49); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               int16_t,
+                               semantic_tag)
+    {
+        write_tag(0x4d);  // little endian
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               int32_t,
+                               semantic_tag)
+    {
+        write_tag(0x4a); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               int32_t,
+                               semantic_tag)
+    {
+        write_tag(0x4e);  // little endian
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               int64_t,
+                               semantic_tag)
+    {
+        write_tag(0x4b); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               int64_t,
+                               semantic_tag)
+    {
+        write_tag(0x4f);  // little endian
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               half_arg_t,
+                               semantic_tag)
+    {
+        write_tag(0x50);
+    }
+    void write_typed_array_tag(std::false_type,
+                               half_arg_t,
+                               semantic_tag)
+    {
+        write_tag(0x54);
+    }
+                        
+    void write_typed_array_tag(std::true_type, 
+                               float,
+                               semantic_tag)
+    {
+        write_tag(0x51); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               float,
+                               semantic_tag)
+    {
+        write_tag(0x55);  // little endian
+    }
+
+    void write_typed_array_tag(std::true_type, 
+                               double,
+                               semantic_tag)
+    {
+        write_tag(0x52); // big endian
+    }
+    void write_typed_array_tag(std::false_type,
+                               double,
+                               semantic_tag)
+    {
+        write_tag(0x56);  // little endian
+    }
+
+    void end_value()
+    {
+        if (!stack_.empty())
+        {
+            ++stack_.back().count_;
+        }
+    }
+};
+
+using cbor_stream_encoder = basic_cbor_encoder<jsoncons::binary_stream_sink>;
+using cbor_bytes_encoder = basic_cbor_encoder<jsoncons::bytes_sink<std::vector<uint8_t>>>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+JSONCONS_DEPRECATED_MSG("Instead, use cbor_bytes_encoder") typedef cbor_bytes_encoder cbor_bytes_serializer;
+
+template<class Sink=jsoncons::binary_stream_sink>
+using basic_cbor_serializer = basic_cbor_encoder<Sink>; 
+
+JSONCONS_DEPRECATED_MSG("Instead, use cbor_stream_encoder") typedef cbor_stream_encoder cbor_encoder;
+JSONCONS_DEPRECATED_MSG("Instead, use cbor_stream_encoder") typedef cbor_stream_encoder cbor_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use cbor_bytes_encoder") typedef cbor_bytes_encoder cbor_buffer_serializer;
+#endif
+
+}}
+#endif
diff --git a/include/jsoncons_ext/cbor/cbor_error.hpp b/include/jsoncons_ext/cbor/cbor_error.hpp
new file mode 100644
index 0000000..a7a6626
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_error.hpp
@@ -0,0 +1,105 @@
+/// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_ERROR_HPP
+#define JSONCONS_CBOR_CBOR_ERROR_HPP
+
+#include <system_error>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_exception.hpp> // jsoncons::ser_error
+
+namespace jsoncons { namespace cbor {
+
+enum class cbor_errc
+{
+    success = 0,
+    unexpected_eof,
+    source_error,
+    invalid_decimal_fraction,
+    invalid_bigfloat,
+    invalid_utf8_text_string,
+    too_many_items,
+    too_few_items,
+    number_too_large,
+    stringref_too_large,
+    max_nesting_depth_exceeded,
+    unknown_type,
+    illegal_chunked_string
+};
+
+class cbor_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/cbor";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<cbor_errc>(ev))
+        {
+            case cbor_errc::unexpected_eof:
+                return "Unexpected end of file";
+            case cbor_errc::source_error:
+                return "Source error";
+            case cbor_errc::invalid_decimal_fraction:
+                return "Invalid decimal fraction";
+            case cbor_errc::invalid_bigfloat:
+                return "Invalid bigfloat";
+            case cbor_errc::invalid_utf8_text_string:
+                return "Illegal UTF-8 encoding in text string";
+            case cbor_errc::too_many_items:
+                return "Too many items were added to a CBOR map or array of known length";
+            case cbor_errc::too_few_items:
+                return "Too few items were added to a CBOR map or array of known length";
+            case cbor_errc::number_too_large:
+                return "Number exceeds implementation limits";
+            case cbor_errc::stringref_too_large:
+                return "stringref exceeds stringref map size";
+            case cbor_errc::max_nesting_depth_exceeded:
+                return "Data item nesting exceeds limit in options";
+            case cbor_errc::unknown_type:
+                return "An unknown type was found in the stream";
+            case cbor_errc::illegal_chunked_string:
+                return "An illegal type was found while parsing an indefinite length string";
+            default:
+                return "Unknown CBOR parser error";
+        }
+    }
+};
+
+inline
+const std::error_category& cbor_error_category()
+{
+  static cbor_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(cbor_errc e)
+{
+    return std::error_code(static_cast<int>(e),cbor_error_category());
+}
+
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+JSONCONS_DEPRECATED_MSG("Instead, use ser_error") typedef ser_error cbor_error;
+JSONCONS_DEPRECATED_MSG("Instead, use ser_error") typedef ser_error cbor_decode_error;
+JSONCONS_DEPRECATED_MSG("Instead, use ser_error") typedef ser_error cbor_reader_errc;
+#endif
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::cbor::cbor_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/cbor/cbor_options.hpp b/include/jsoncons_ext/cbor/cbor_options.hpp
new file mode 100644
index 0000000..1de4a4e
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_options.hpp
@@ -0,0 +1,113 @@
+// Copyright 2019 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_OPTIONS_HPP
+#define JSONCONS_CBOR_CBOR_OPTIONS_HPP
+
+#include <string>
+#include <limits> // std::numeric_limits
+#include <cwchar>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons_ext/cbor/cbor_detail.hpp>
+
+namespace jsoncons { namespace cbor {
+
+class cbor_options;
+
+class cbor_options_common
+{
+    friend class cbor_options;
+
+    int max_nesting_depth_;
+protected:
+    virtual ~cbor_options_common() = default;
+
+    cbor_options_common()
+        : max_nesting_depth_(1024)
+    {
+    }
+
+    cbor_options_common(const cbor_options_common&) = default;
+    cbor_options_common& operator=(const cbor_options_common&) = default;
+    cbor_options_common(cbor_options_common&&) = default;
+    cbor_options_common& operator=(cbor_options_common&&) = default;
+public:
+    int max_nesting_depth() const 
+    {
+        return max_nesting_depth_;
+    }
+};
+
+class cbor_decode_options : public virtual cbor_options_common
+{
+    friend class cbor_options;
+public:
+    cbor_decode_options()
+    {
+    }
+};
+
+class cbor_encode_options : public virtual cbor_options_common
+{
+    friend class cbor_options;
+
+    bool use_stringref_;
+    bool use_typed_arrays_;
+public:
+    cbor_encode_options()
+        : use_stringref_(false),
+          use_typed_arrays_(false)
+    {
+    }
+
+    bool pack_strings() const 
+    {
+        return use_stringref_;
+    }
+
+    bool use_typed_arrays() const 
+    {
+        return use_typed_arrays_;
+    }
+};
+
+class cbor_options final : public cbor_decode_options, public cbor_encode_options
+{
+public:
+    using cbor_options_common::max_nesting_depth;
+    using cbor_encode_options::pack_strings;
+    using cbor_encode_options::use_typed_arrays;
+
+    cbor_options& max_nesting_depth(int value)
+    {
+        this->max_nesting_depth_ = value;
+        return *this;
+    }
+
+    cbor_options& pack_strings(bool value)
+    {
+        this->use_stringref_ = value;
+        return *this;
+    }
+
+    cbor_options& use_typed_arrays(bool value)
+    {
+        this->use_typed_arrays_ = value;
+        return *this;
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+    JSONCONS_DEPRECATED_MSG("Instead, use use_typed_arrays(bool)")
+    cbor_options& enable_typed_arrays(bool value)
+    {
+        this->use_typed_arrays_ = value;
+        return *this;
+    }
+#endif
+};
+
+}}
+#endif
diff --git a/include/jsoncons_ext/cbor/cbor_parser.hpp b/include/jsoncons_ext/cbor/cbor_parser.hpp
new file mode 100644
index 0000000..f3d03bb
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_parser.hpp
@@ -0,0 +1,1942 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_PARSER_HPP
+#define JSONCONS_CBOR_CBOR_PARSER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <utility> // std::move
+#include <bitset> // std::bitset
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/cbor/cbor_error.hpp>
+#include <jsoncons_ext/cbor/cbor_detail.hpp>
+#include <jsoncons_ext/cbor/cbor_options.hpp>
+#include <jsoncons/json_visitor2.hpp>
+
+namespace jsoncons { namespace cbor {
+
+enum class parse_mode {root,accept,array,indefinite_array,map_key,map_value,indefinite_map_key,indefinite_map_value,multi_dim};
+
+struct mapped_string
+{
+    jsoncons::cbor::detail::cbor_major_type type;
+    std::string s;
+    std::vector<uint8_t> bytes;
+
+    mapped_string(const std::string& s)
+        : type(jsoncons::cbor::detail::cbor_major_type::text_string), s(s)
+    {
+    }
+
+    mapped_string(std::string&& s)
+        : type(jsoncons::cbor::detail::cbor_major_type::text_string), s(std::move(s))
+    {
+    }
+
+    mapped_string(const std::vector<uint8_t>& bytes)
+        : type(jsoncons::cbor::detail::cbor_major_type::byte_string), bytes(bytes)
+    {
+    }
+
+    mapped_string(std::vector<uint8_t>&& bytes)
+        : type(jsoncons::cbor::detail::cbor_major_type::byte_string), bytes(std::move(bytes))
+    {
+    }
+
+    mapped_string(const mapped_string&) = default;
+
+    mapped_string(mapped_string&&) = default;
+
+    mapped_string& operator=(const mapped_string&) = default;
+
+    mapped_string& operator=(mapped_string&&) = default;
+};
+
+struct parse_state 
+{
+    parse_mode mode; 
+    std::size_t length;
+    std::size_t index;
+    bool pop_stringref_map_stack;
+
+    parse_state(parse_mode mode, std::size_t length, bool pop_stringref_map_stack = false) noexcept
+        : mode(mode), length(length), index(0), pop_stringref_map_stack(pop_stringref_map_stack)
+    {
+    }
+
+    parse_state(const parse_state&) = default;
+    parse_state(parse_state&&) = default;
+};
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_cbor_parser : public ser_context
+{
+    using char_type = char;
+    using char_traits_type = std::char_traits<char>;
+    using allocator_type = Allocator;
+    using char_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<char_type>;
+    using byte_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<uint8_t>;                  
+    using tag_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<uint64_t>;                 
+    using parse_state_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<parse_state>;                         
+    using stringref_map = std::vector<mapped_string>;
+    using stringref_map_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<stringref_map>;                           
+
+    using string_type = std::basic_string<char_type,char_traits_type,char_allocator_type>;
+
+    enum {stringref_tag, // 25
+          stringref_namespace_tag, // 256
+          item_tag,
+          num_of_tags};
+
+    std::bitset<num_of_tags> other_tags_;
+
+    allocator_type alloc_;
+    Source source_;
+    cbor_decode_options options_;
+
+    bool more_;
+    bool done_;
+    string_type text_buffer_;
+    std::vector<uint8_t,byte_allocator_type> bytes_buffer_;
+    uint64_t item_tag_;
+    std::vector<parse_state,parse_state_allocator_type> state_stack_;
+    std::vector<uint8_t,byte_allocator_type> typed_array_;
+    std::vector<std::size_t> shape_;
+    std::size_t index_; // TODO: Never used!
+    std::vector<stringref_map,stringref_map_allocator_type> stringref_map_stack_;
+    int nesting_depth_;
+
+    struct read_byte_string_from_buffer
+    {
+        byte_string_view bytes;
+
+        read_byte_string_from_buffer(const byte_string_view& b)
+            : bytes(b)
+        {
+        }
+        template <class Container>
+        void operator()(Container& c, std::error_code&)
+        {
+            c.clear();
+            c.reserve(bytes.size());
+            for (auto b : bytes)
+            {
+                c.push_back(b);
+            }
+        }
+    };
+
+    struct read_byte_string_from_source
+    {
+        basic_cbor_parser<Source,Allocator>* source;
+
+        read_byte_string_from_source(basic_cbor_parser<Source,Allocator>* source)
+            : source(source)
+        {
+        }
+        template <class Container>
+        void operator()(Container& c, std::error_code& ec)
+        {
+            source->read_byte_string(c,ec);
+        }
+    };
+
+public:
+    template <class Sourceable>
+    basic_cbor_parser(Sourceable&& source,
+                      const cbor_decode_options& options = cbor_decode_options(),
+                      const Allocator alloc = Allocator())
+       : alloc_(alloc),
+         source_(std::forward<Sourceable>(source)),
+         options_(options),
+         more_(true), 
+         done_(false),
+         text_buffer_(alloc),
+         bytes_buffer_(alloc),
+         item_tag_(0),
+         state_stack_(alloc),
+         typed_array_(alloc),
+         index_(0),
+         stringref_map_stack_(alloc),
+         nesting_depth_(0)
+    {
+        state_stack_.emplace_back(parse_mode::root,0);
+    }
+
+    void restart()
+    {
+        more_ = true;
+    }
+
+    void reset()
+    {
+        more_ = true;
+        done_ = false;
+        text_buffer_.clear();
+        bytes_buffer_.clear();
+        item_tag_ = 0;
+        state_stack_.clear();
+        state_stack_.emplace_back(parse_mode::root,0);
+        typed_array_.clear();
+        stringref_map_stack_.clear();
+        nesting_depth_ = 0;
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        source_ = std::forward<Sourceable>(source);
+        reset();
+    }
+
+    bool done() const
+    {
+        return done_;
+    }
+
+    bool stopped() const
+    {
+        return !more_;
+    }
+
+    std::size_t line() const override
+    {
+        return 0;
+    }
+
+    std::size_t column() const override
+    {
+        return source_.position();
+    }
+
+    void parse(json_visitor2& visitor, std::error_code& ec)
+    {
+        while (!done_ && more_)
+        {
+            switch (state_stack_.back().mode)
+            {
+                case parse_mode::multi_dim:
+                {
+                    if (state_stack_.back().index == 0)
+                    {
+                        ++state_stack_.back().index;
+                        read_item(visitor, ec);
+                    }
+                    else
+                    {
+                        produce_end_multi_dim(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::array:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        read_item(visitor, ec);
+                    }
+                    else
+                    {
+                        end_array(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::indefinite_array:
+                {
+                    auto c = source_.peek();
+                    if (c.eof)
+                    {
+                        ec = cbor_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (c.value == 0xff)
+                    {
+                        source_.ignore(1);
+                        end_array(visitor, ec);
+                    }
+                    else
+                    {
+                        read_item(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::map_key:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        state_stack_.back().mode = parse_mode::map_value;
+                        read_item(visitor, ec);
+                    }
+                    else
+                    {
+                        end_object(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::map_value:
+                {
+                    state_stack_.back().mode = parse_mode::map_key;
+                    read_item(visitor, ec);
+                    break;
+                }
+                case parse_mode::indefinite_map_key:
+                {
+                    auto c = source_.peek();
+                    if (c.eof)
+                    {
+                        ec = cbor_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (c.value == 0xff)
+                    {
+                        source_.ignore(1);
+                        end_object(visitor, ec);
+                    }
+                    else
+                    {
+                        state_stack_.back().mode = parse_mode::indefinite_map_value;
+                        read_item(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::indefinite_map_value:
+                {
+                    state_stack_.back().mode = parse_mode::indefinite_map_key;
+                    read_item(visitor, ec);
+                    break;
+                }
+                case parse_mode::root:
+                {
+                    state_stack_.back().mode = parse_mode::accept;
+                    read_item(visitor, ec);
+                    break;
+                }
+                case parse_mode::accept:
+                {
+                    JSONCONS_ASSERT(state_stack_.size() == 1);
+                    state_stack_.clear();
+                    more_ = false;
+                    done_ = true;
+                    visitor.flush();
+                    break;
+                }
+            }
+        }
+    }
+private:
+    void read_item(json_visitor2& visitor, std::error_code& ec)
+    {
+        read_tags(ec);
+        if (!more_)
+        {
+            return;
+        }
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(c.value);
+        uint8_t info = get_additional_information_value(c.value);
+
+        switch (major_type)
+        {
+            case jsoncons::cbor::detail::cbor_major_type::unsigned_integer:
+            {
+                uint64_t val = get_uint64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                if (!stringref_map_stack_.empty() && other_tags_[stringref_tag])
+                {
+                    other_tags_[stringref_tag] = false;
+                    if (val >= stringref_map_stack_.back().size())
+                    {
+                        ec = cbor_errc::stringref_too_large;
+                        more_ = false;
+                        return;
+                    }
+                    stringref_map::size_type index = (stringref_map::size_type)val;
+                    if (index != val)
+                    {
+                        ec = cbor_errc::number_too_large;
+                        more_ = false;
+                        return;
+                    }
+                    auto& str = stringref_map_stack_.back().at(index);
+                    switch (str.type)
+                    {
+                        case jsoncons::cbor::detail::cbor_major_type::text_string:
+                        {
+                            handle_string(visitor, jsoncons::basic_string_view<char>(str.s.data(),str.s.length()),ec);
+                            if (ec)
+                            {
+                                return;
+                            }
+                            break;
+                        }
+                        case jsoncons::cbor::detail::cbor_major_type::byte_string:
+                        {
+                            read_byte_string_from_buffer read(byte_string_view(str.bytes));
+                            write_byte_string(read, visitor, ec);
+                            if (ec)
+                            {
+                                return;
+                            }
+                            break;
+                        }
+                        default:
+                            JSONCONS_UNREACHABLE();
+                            break;
+                    }
+                }
+                else
+                {
+                    semantic_tag tag = semantic_tag::none;
+                    if (other_tags_[item_tag])
+                    {
+                        if (item_tag_ == 1)
+                        {
+                            tag = semantic_tag::epoch_second;
+                        }
+                        other_tags_[item_tag] = false;
+                    }
+                    more_ = visitor.uint64_value(val, tag, *this, ec);
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::negative_integer:
+            {
+                int64_t val = get_int64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                semantic_tag tag = semantic_tag::none;
+                if (other_tags_[item_tag])
+                {
+                    if (item_tag_ == 1)
+                    {
+                        tag = semantic_tag::epoch_second;
+                    }
+                    other_tags_[item_tag] = false;
+                }
+                more_ = visitor.int64_value(val, tag, *this, ec);
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::byte_string:
+            {
+                read_byte_string_from_source read(this);
+                write_byte_string(read, visitor, ec);
+                if (ec)
+                {
+                    return;
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::text_string:
+            {
+                text_buffer_.clear();
+                read_text_string(text_buffer_, ec);
+                if (ec)
+                {
+                    return;
+                }
+                auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+                if (result.ec != unicode_traits::conv_errc())
+                {
+                    ec = cbor_errc::invalid_utf8_text_string;
+                    more_ = false;
+                    return;
+                }
+                handle_string(visitor, jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()),ec);
+                if (ec)
+                {
+                    return;
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::semantic_tag:
+            {
+                JSONCONS_UNREACHABLE();
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::simple:
+            {
+                switch (info)
+                {
+                    case 0x14:
+                        more_ = visitor.bool_value(false, semantic_tag::none, *this, ec);
+                        source_.ignore(1);
+                        break;
+                    case 0x15:
+                        more_ = visitor.bool_value(true, semantic_tag::none, *this, ec);
+                        source_.ignore(1);
+                        break;
+                    case 0x16:
+                        more_ = visitor.null_value(semantic_tag::none, *this, ec);
+                        source_.ignore(1);
+                        break;
+                    case 0x17:
+                        more_ = visitor.null_value(semantic_tag::undefined, *this, ec);
+                        source_.ignore(1);
+                        break;
+                    case 0x19: // Half-Precision Float (two-byte IEEE 754)
+                    {
+                        uint64_t val = get_uint64_value(ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                        more_ = visitor.half_value(static_cast<uint16_t>(val), semantic_tag::none, *this, ec);
+                        break;
+                    }
+                    case 0x1a: // Single-Precision Float (four-byte IEEE 754)
+                    case 0x1b: // Double-Precision Float (eight-byte IEEE 754)
+                    {
+                        double val = get_double(ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                        semantic_tag tag = semantic_tag::none;
+                        if (other_tags_[item_tag])
+                        {
+                            if (item_tag_ == 1)
+                            {
+                                tag = semantic_tag::epoch_second;
+                            }
+                            other_tags_[item_tag] = false;
+                        }
+                        more_ = visitor.double_value(val, tag, *this, ec);
+                        break;
+                    }
+                    default:
+                    {
+                        ec = cbor_errc::unknown_type;
+                        more_ = false;
+                        return;
+                    }
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::array:
+            {
+                if (other_tags_[item_tag])
+                {
+                    switch (item_tag_)
+                    {
+                        case 0x04:
+                            text_buffer_.clear();
+                            read_decimal_fraction(text_buffer_, ec);
+                            if (ec)
+                            {
+                                return;
+                            }
+                            more_ = visitor.string_value(text_buffer_, semantic_tag::bigdec, *this, ec);
+                            break;
+                        case 0x05:
+                            text_buffer_.clear();
+                            read_bigfloat(text_buffer_, ec);
+                            if (ec)
+                            {
+                                return;
+                            }
+                            more_ = visitor.string_value(text_buffer_, semantic_tag::bigfloat, *this, ec);
+                            break;
+                        case 40: // row major storage
+                            produce_begin_multi_dim(visitor, semantic_tag::multi_dim_row_major, ec);
+                            break;
+                        case 1040: // column major storage
+                            produce_begin_multi_dim(visitor, semantic_tag::multi_dim_column_major, ec);
+                            break;
+                        default:
+                            begin_array(visitor, info, ec);
+                            break;
+                    }
+                    other_tags_[item_tag] = false;
+                }
+                else
+                {
+                    begin_array(visitor, info, ec);
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::map:
+            {
+                begin_object(visitor, info, ec);
+                break;
+            }
+            default:
+                break;
+        }
+        other_tags_[item_tag] = false;
+    }
+
+    void begin_array(json_visitor2& visitor, uint8_t info, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = cbor_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+        semantic_tag tag = semantic_tag::none;
+        bool pop_stringref_map_stack = false;
+        if (other_tags_[stringref_namespace_tag])
+        {
+            stringref_map_stack_.emplace_back(alloc_);
+            other_tags_[stringref_namespace_tag] = false;
+            pop_stringref_map_stack = true;
+        }
+        switch (info)
+        {
+            case jsoncons::cbor::detail::additional_info::indefinite_length:
+            {
+                state_stack_.emplace_back(parse_mode::indefinite_array,0,pop_stringref_map_stack);
+                more_ = visitor.begin_array(tag, *this, ec);
+                source_.ignore(1);
+                break;
+            }
+            default: // definite length
+            {
+                std::size_t len = get_size(ec);
+                if (!more_)
+                {
+                    return;
+                }
+                state_stack_.emplace_back(parse_mode::array,len,pop_stringref_map_stack);
+                more_ = visitor.begin_array(len, tag, *this, ec);
+                break;
+            }
+        }
+    }
+
+    void end_array(json_visitor2& visitor, std::error_code& ec)
+    {
+        --nesting_depth_;
+
+        more_ = visitor.end_array(*this, ec);
+        if (state_stack_.back().pop_stringref_map_stack)
+        {
+            stringref_map_stack_.pop_back();
+        }
+        state_stack_.pop_back();
+    }
+
+    void begin_object(json_visitor2& visitor, uint8_t info, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = cbor_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+        bool pop_stringref_map_stack = false;
+        if (other_tags_[stringref_namespace_tag])
+        {
+            stringref_map_stack_.emplace_back(alloc_);
+            other_tags_[stringref_namespace_tag] = false;
+            pop_stringref_map_stack = true;
+        }
+        switch (info)
+        {
+            case jsoncons::cbor::detail::additional_info::indefinite_length: 
+            {
+                state_stack_.emplace_back(parse_mode::indefinite_map_key,0,pop_stringref_map_stack);
+                more_ = visitor.begin_object(semantic_tag::none, *this, ec);
+                source_.ignore(1);
+                break;
+            }
+            default: // definite_length
+            {
+                std::size_t len = get_size(ec);
+                if (!more_)
+                {
+                    return;
+                }
+                state_stack_.emplace_back(parse_mode::map_key,len,pop_stringref_map_stack);
+                more_ = visitor.begin_object(len, semantic_tag::none, *this, ec);
+                break;
+            }
+        }
+    }
+
+    void end_object(json_visitor2& visitor, std::error_code& ec)
+    {
+        --nesting_depth_;
+        more_ = visitor.end_object(*this, ec);
+        if (state_stack_.back().pop_stringref_map_stack)
+        {
+            stringref_map_stack_.pop_back();
+        }
+        state_stack_.pop_back();
+    }
+
+    void read_text_string(string_type& s, std::error_code& ec)
+    {
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(c.value);
+        uint8_t info = get_additional_information_value(c.value);
+
+        JSONCONS_ASSERT(major_type == jsoncons::cbor::detail::cbor_major_type::text_string);
+        auto func = [&s](Source& source, std::size_t length, std::error_code& ec) -> bool
+        {
+            if (source_reader<Source>::read(source, s, length) != length)
+            {
+                ec = cbor_errc::unexpected_eof;
+                return false;
+            }
+            return true;
+        };
+        iterate_string_chunks(func, major_type, ec);
+        if (!stringref_map_stack_.empty() && 
+            info != jsoncons::cbor::detail::additional_info::indefinite_length &&
+            s.length() >= jsoncons::cbor::detail::min_length_for_stringref(stringref_map_stack_.back().size()))
+        {
+            stringref_map_stack_.back().emplace_back(s);
+        }
+    }
+
+    std::size_t get_size(std::error_code& ec)
+    {
+        uint64_t u = get_uint64_value(ec);
+        if (!more_)
+        {
+            return 0;
+        }
+        std::size_t len = static_cast<std::size_t>(u);
+        if (len != u)
+        {
+            ec = cbor_errc::number_too_large;
+            more_ = false;
+        }
+        return len;
+    }
+
+    bool read_byte_string(std::vector<uint8_t,byte_allocator_type>& v, std::error_code& ec)
+    {
+        bool more = true;
+        v.clear();
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more = false;
+            return more;
+        }
+        jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(c.value);
+        uint8_t info = get_additional_information_value(c.value);
+
+        JSONCONS_ASSERT(major_type == jsoncons::cbor::detail::cbor_major_type::byte_string);
+
+        switch(info)
+        {
+            case jsoncons::cbor::detail::additional_info::indefinite_length:
+            {
+                auto func = [&v,&more](Source& source, std::size_t length, std::error_code& ec) -> bool
+                {
+                    if (source_reader<Source>::read(source, v, length) != length)
+                    {
+                        ec = cbor_errc::unexpected_eof;
+                        more = false;
+                        return more;
+                    }
+                    return true;
+                };
+                iterate_string_chunks(func, major_type, ec);
+                break;
+            }
+            default:
+            {
+                std::size_t length = get_size(ec);
+                if (ec)
+                {
+                    more = false;
+                    return more;
+                }
+                if (source_reader<Source>::read(source_, v, length) != length)
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more = false;
+                    return more;
+                }
+                if (!stringref_map_stack_.empty() &&
+                    v.size() >= jsoncons::cbor::detail::min_length_for_stringref(stringref_map_stack_.back().size()))
+                {
+                    stringref_map_stack_.back().emplace_back(v);
+                }
+                break;
+            }
+        }
+        return more;
+    }
+
+    template <class Function>
+    void iterate_string_chunks(Function& func, jsoncons::cbor::detail::cbor_major_type type, std::error_code& ec)
+    {
+        int nesting_level = 0;
+
+        bool done = false;
+        while (!done)
+        {
+            auto c = source_.peek();
+            if (c.eof)
+            {
+                ec = cbor_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            if (nesting_level > 0 && c.value == 0xff)
+            {
+                --nesting_level;
+                if (nesting_level == 0)
+                {
+                    done = true;
+                }
+                source_.ignore(1);
+                continue;
+            }
+
+            jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(c.value);
+            if (major_type != type)
+            {
+                ec = cbor_errc::illegal_chunked_string;
+                more_ = false;
+                return;
+            }
+            uint8_t info = get_additional_information_value(c.value);
+
+            switch (info)
+            {
+                case jsoncons::cbor::detail::additional_info::indefinite_length:
+                {
+                    ++nesting_level;
+                    source_.ignore(1);
+                    break;
+                }
+                default: // definite length
+                {
+                    std::size_t length = get_size(ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+                    more_ = func(source_, length, ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+                    if (nesting_level == 0)
+                    {
+                        done = true;
+                    }
+                    break;
+                }
+            }
+        } 
+    }
+
+    uint64_t get_uint64_value(std::error_code& ec)
+    {
+        uint64_t val = 0;
+
+        uint8_t initial_b;
+        if (source_.read(&initial_b, 1) == 0)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return 0;
+        }
+        uint8_t info = get_additional_information_value(initial_b);
+        switch (info)
+        {
+            case JSONCONS_CBOR_0x00_0x17: // Integer 0x00..0x17 (0..23)
+            {
+                val = info;
+                break;
+            }
+
+            case 0x18: // Unsigned integer (one-byte uint8_t follows)
+            {
+                uint8_t b;
+                if (source_.read(&b, 1) == 0)
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return val;
+                }
+                val = b;
+                break;
+            }
+
+            case 0x19: // Unsigned integer (two-byte uint16_t follows)
+            {
+                uint8_t buf[sizeof(uint16_t)];
+                source_.read(buf, sizeof(uint16_t));
+                val = binary::big_to_native<uint16_t>(buf, sizeof(buf));
+                break;
+            }
+
+            case 0x1a: // Unsigned integer (four-byte uint32_t follows)
+            {
+                uint8_t buf[sizeof(uint32_t)];
+                source_.read(buf, sizeof(uint32_t));
+                val = binary::big_to_native<uint32_t>(buf, sizeof(buf));
+                break;
+            }
+
+            case 0x1b: // Unsigned integer (eight-byte uint64_t follows)
+            {
+                uint8_t buf[sizeof(uint64_t)];
+                source_.read(buf, sizeof(uint64_t));
+                val = binary::big_to_native<uint64_t>(buf, sizeof(buf));
+                break;
+            }
+            default:
+                break;
+        }
+        return val;
+    }
+
+    int64_t get_int64_value(std::error_code& ec)
+    {
+        int64_t val = 0;
+
+        auto ch = source_.peek();
+        if (ch.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return val;
+        }
+
+        jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(ch.value);
+        uint8_t info = get_additional_information_value(ch.value);
+        switch (major_type)
+        {
+            case jsoncons::cbor::detail::cbor_major_type::negative_integer:
+                source_.ignore(1);
+                switch (info)
+                {
+                    case JSONCONS_CBOR_0x00_0x17: // 0x00..0x17 (0..23)
+                    {
+                        val = static_cast<int8_t>(- 1 - info);
+                        break;
+                    }
+                    case 0x18: // Negative integer (one-byte uint8_t follows)
+                        {
+                            uint8_t b;
+                            if (source_.read(&b, 1) == 0)
+                            {
+                                ec = cbor_errc::unexpected_eof;
+                                more_ = false;
+                                return val;
+                            }
+                            val = static_cast<int64_t>(-1) - static_cast<int64_t>(b);
+                            break;
+                        }
+
+                    case 0x19: // Negative integer -1-n (two-byte uint16_t follows)
+                        {
+                            uint8_t buf[sizeof(uint16_t)];
+                            if (source_.read(buf, sizeof(uint16_t)) != sizeof(uint16_t))
+                            {
+                                ec = cbor_errc::unexpected_eof;
+                                more_ = false;
+                                return val;
+                            }
+                            auto x = binary::big_to_native<uint16_t>(buf, sizeof(buf));
+                            val = static_cast<int64_t>(-1)- x;
+                            break;
+                        }
+
+                    case 0x1a: // Negative integer -1-n (four-byte uint32_t follows)
+                        {
+                            uint8_t buf[sizeof(uint32_t)];
+                            if (source_.read(buf, sizeof(uint32_t)) != sizeof(uint32_t))
+                            {
+                                ec = cbor_errc::unexpected_eof;
+                                more_ = false;
+                                return val;
+                            }
+                            auto x = binary::big_to_native<uint32_t>(buf, sizeof(buf));
+                            val = static_cast<int64_t>(-1)- x;
+                            break;
+                        }
+
+                    case 0x1b: // Negative integer -1-n (eight-byte uint64_t follows)
+                        {
+                            uint8_t buf[sizeof(uint64_t)];
+                            if (source_.read(buf, sizeof(uint64_t)) != sizeof(uint64_t))
+                            {
+                                ec = cbor_errc::unexpected_eof;
+                                more_ = false;
+                                return val;
+                            }
+                            auto x = binary::big_to_native<uint64_t>(buf, sizeof(buf));
+                            val = static_cast<int64_t>(-1)- static_cast<int64_t>(x);
+                            break;
+                        }
+                }
+                break;
+
+                case jsoncons::cbor::detail::cbor_major_type::unsigned_integer:
+                {
+                    uint64_t x = get_uint64_value(ec);
+                    if (ec)
+                    {
+                        return 0;
+                    }
+                    if (x <= static_cast<uint64_t>((std::numeric_limits<int64_t>::max)()))
+                    {
+                        val = x;
+                    }
+                    else
+                    {
+                        // error;
+                    }
+                    
+                    break;
+                }
+                break;
+            default:
+                break;
+        }
+
+        return val;
+    }
+
+    double get_double(std::error_code& ec)
+    {
+        double val = 0;
+
+        uint8_t b;
+        if (source_.read(&b, 1) == 0)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return 0;
+        }
+        uint8_t info = get_additional_information_value(b);
+        switch (info)
+        {
+        case 0x1a: // Single-Precision Float (four-byte IEEE 754)
+            {
+                uint8_t buf[sizeof(float)];
+                if (source_.read(buf, sizeof(float)) !=sizeof(float)) 
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return 0;
+                }
+                val = binary::big_to_native<float>(buf, sizeof(buf));
+                break;
+            }
+
+        case 0x1b: //  Double-Precision Float (eight-byte IEEE 754)
+            {
+                uint8_t buf[sizeof(double)];
+                if (source_.read(buf, sizeof(double)) != sizeof(double))
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return 0;
+                }
+                val = binary::big_to_native<double>(buf, sizeof(buf));
+                break;
+            }
+            default:
+                break;
+        }
+        
+        return val;
+    }
+
+    void read_decimal_fraction(string_type& result, std::error_code& ec)
+    {
+        std::size_t size = get_size(ec);
+        if (!more_)
+        {
+            return;
+        }
+        if (size != 2)
+        {
+            ec = cbor_errc::invalid_decimal_fraction;
+            more_ = false;
+            return;
+        }
+
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        int64_t exponent = 0;
+        switch (get_major_type(c.value))
+        {
+            case jsoncons::cbor::detail::cbor_major_type::unsigned_integer:
+            {
+                exponent = get_uint64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::negative_integer:
+            {
+                exponent = get_int64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                break;
+            }
+            default:
+            {
+                ec = cbor_errc::invalid_decimal_fraction;
+                more_ = false;
+                return;
+            }
+        }
+
+        string_type s;
+
+        c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+
+        switch (get_major_type(c.value))
+        {
+            case jsoncons::cbor::detail::cbor_major_type::unsigned_integer:
+            {
+                uint64_t val = get_uint64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                jsoncons::detail::from_integer(val, s);
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::negative_integer:
+            {
+                int64_t val = get_int64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                jsoncons::detail::from_integer(val, s);
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::semantic_tag:
+            {
+                uint8_t b;
+                if (source_.read(&b, 1) == 0)
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                uint8_t tag = get_additional_information_value(b);
+                c = source_.peek();
+                if (c.eof)
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                if (get_major_type(c.value) == jsoncons::cbor::detail::cbor_major_type::byte_string)
+                {
+                    bytes_buffer_.clear();
+                    read_byte_string(bytes_buffer_, ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    if (tag == 2)
+                    {
+                        bigint n = bigint::from_bytes_be(1, bytes_buffer_.data(), bytes_buffer_.size());
+                        n.write_string(s);
+                    }
+                    else if (tag == 3)
+                    {
+                        bigint n = bigint::from_bytes_be(1, bytes_buffer_.data(), bytes_buffer_.size());
+                        n = -1 - n;
+                        n.write_string(s);
+                    }
+                }
+                break;
+            }
+            default:
+            {
+                ec = cbor_errc::invalid_decimal_fraction;
+                more_ = false;
+                return;
+            }
+        }
+
+        if (s.size() >= static_cast<std::size_t>((std::numeric_limits<int32_t>::max)()) || 
+            exponent >= (std::numeric_limits<int32_t>::max)() || 
+            exponent <= (std::numeric_limits<int32_t>::min)())
+        {
+            ec = cbor_errc::invalid_decimal_fraction;
+            more_ = false;
+            return;
+        }
+        else if (s.size() > 0)
+        {
+            if (s[0] == '-')
+            {
+                result.push_back('-');
+                jsoncons::detail::prettify_string(s.c_str()+1, s.size()-1, (int)exponent, -4, 17, result);
+            }
+            else
+            {
+                jsoncons::detail::prettify_string(s.c_str(), s.size(), (int)exponent, -4, 17, result);
+            }
+        }
+        else
+        {
+            ec = cbor_errc::invalid_decimal_fraction;
+            more_ = false;
+            return;
+        }
+    }
+
+    void read_bigfloat(string_type& s, std::error_code& ec)
+    {
+        std::size_t size = get_size(ec);
+        if (!more_)
+        {
+            return;
+        }
+        if (size != 2)
+        {
+            ec = cbor_errc::invalid_bigfloat;
+            more_ = false;
+            return;
+        }
+
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        int64_t exponent = 0;
+        switch (get_major_type(c.value))
+        {
+            case jsoncons::cbor::detail::cbor_major_type::unsigned_integer:
+            {
+                exponent = get_uint64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::negative_integer:
+            {
+                exponent = get_int64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                break;
+            }
+            default:
+            {
+                ec = cbor_errc::invalid_bigfloat;
+                more_ = false;
+                return;
+            }
+        }
+
+        c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        switch (get_major_type(c.value))
+        {
+            case jsoncons::cbor::detail::cbor_major_type::unsigned_integer:
+            {
+                uint64_t val = get_uint64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                s.push_back('0');
+                s.push_back('x');
+                jsoncons::detail::integer_to_string_hex(val, s);
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::negative_integer:
+            {
+                int64_t val = get_int64_value(ec);
+                if (ec)
+                {
+                    return;
+                }
+                s.push_back('-');
+                s.push_back('0');
+                s.push_back('x');
+                jsoncons::detail::integer_to_string_hex(static_cast<uint64_t>(-val), s);
+                break;
+            }
+            case jsoncons::cbor::detail::cbor_major_type::semantic_tag:
+            {
+                uint8_t b;
+                if (source_.read(&b, 1) == 0)
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                uint8_t tag = get_additional_information_value(b);
+
+                c = source_.peek();
+                if (c.eof)
+                {
+                    ec = cbor_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                if (get_major_type(c.value) == jsoncons::cbor::detail::cbor_major_type::byte_string)
+                {
+                    bytes_buffer_.clear(); 
+                    more_ = read_byte_string(bytes_buffer_, ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+                    if (tag == 2)
+                    {
+                        s.push_back('0');
+                        s.push_back('x');
+                        bigint n = bigint::from_bytes_be(1, bytes_buffer_.data(), bytes_buffer_.size());
+                        n.write_string_hex(s);
+                    }
+                    else if (tag == 3)
+                    {
+                        s.push_back('-');
+                        s.push_back('0');
+                        bigint n = bigint::from_bytes_be(1, bytes_buffer_.data(), bytes_buffer_.size());
+                        n = -1 - n;
+                        n.write_string_hex(s);
+                        s[2] = 'x'; // overwrite minus
+                    }
+                }
+                break;
+            }
+            default:
+            {
+                ec = cbor_errc::invalid_bigfloat;
+                more_ = false;
+                return;
+            }
+        }
+
+        s.push_back('p');
+        if (exponent >=0)
+        {
+            jsoncons::detail::integer_to_string_hex(static_cast<uint64_t>(exponent), s);
+        }
+        else
+        {
+            s.push_back('-');
+            jsoncons::detail::integer_to_string_hex(static_cast<uint64_t>(-exponent), s);
+        }
+    }
+
+    static jsoncons::cbor::detail::cbor_major_type get_major_type(uint8_t type)
+    {
+        static constexpr uint8_t major_type_shift = 0x05;
+        uint8_t value = type >> major_type_shift;
+        return static_cast<jsoncons::cbor::detail::cbor_major_type>(value);
+    }
+
+    static uint8_t get_additional_information_value(uint8_t type)
+    {
+        static constexpr uint8_t additional_information_mask = (1U << 5) - 1;
+        uint8_t value = type & additional_information_mask;
+        return value;
+    }
+
+    void read_tags(std::error_code& ec)
+    {
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(c.value);
+
+        while (major_type == jsoncons::cbor::detail::cbor_major_type::semantic_tag)
+        {
+            uint64_t val = get_uint64_value(ec);
+            if (!more_)
+            {
+                return;
+            }
+            switch(val)
+            {
+                case 25: // stringref
+                    other_tags_[stringref_tag] = true;
+                    break;
+                case 256: // stringref-namespace
+                    other_tags_[stringref_namespace_tag] = true;
+                    break;
+                default:
+                    other_tags_[item_tag] = true;
+                    item_tag_ = val;
+                    break;
+            }
+            c = source_.peek();
+            if (c.eof)
+            {
+                ec = cbor_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            major_type = get_major_type(c.value);
+        }
+    }
+
+    void handle_string(json_visitor2& visitor, const jsoncons::basic_string_view<char>& v, std::error_code& ec)
+    {
+        semantic_tag tag = semantic_tag::none;
+        if (other_tags_[item_tag])
+        {
+            switch (item_tag_)
+            {
+                case 0:
+                    tag = semantic_tag::datetime;
+                    break;
+                case 32:
+                    tag = semantic_tag::uri;
+                    break;
+                case 33:
+                    tag = semantic_tag::base64url;
+                    break;
+                case 34:
+                    tag = semantic_tag::base64;
+                    break;
+                default:
+                    break;
+            }
+            other_tags_[item_tag] = false;
+        }
+        more_ = visitor.string_value(v, tag, *this, ec);
+    }
+
+    static jsoncons::endian get_typed_array_endianness(const uint8_t tag)
+    {
+        return ((tag & detail::cbor_array_tags_e_mask) >> detail::cbor_array_tags_e_shift) == 0 ? jsoncons::endian::big : jsoncons::endian::little; 
+    }
+
+    static std::size_t get_typed_array_bytes_per_element(const uint8_t tag)
+    {
+        const uint8_t f = (tag & detail::cbor_array_tags_f_mask) >> detail::cbor_array_tags_f_shift; 
+        const uint8_t ll = (tag & detail::cbor_array_tags_ll_mask) >> detail::cbor_array_tags_ll_shift; 
+
+        return std::size_t(1) << (f + ll); 
+    }
+
+    template <typename Read>
+    void write_byte_string(Read read, json_visitor2& visitor, std::error_code& ec)
+    {
+        if (other_tags_[item_tag])
+        {
+            switch (item_tag_)
+            {
+                case 0x2:
+                {
+                    bytes_buffer_.clear();
+                    read(bytes_buffer_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    bigint n = bigint::from_bytes_be(1, bytes_buffer_.data(), bytes_buffer_.size());
+                    text_buffer_.clear();
+                    n.write_string(text_buffer_);
+                    more_ = visitor.string_value(text_buffer_, semantic_tag::bigint, *this, ec);
+                    break;
+                }
+                case 0x3:
+                {
+                    bytes_buffer_.clear();
+                    read(bytes_buffer_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    bigint n = bigint::from_bytes_be(1, bytes_buffer_.data(), bytes_buffer_.size());
+                    n = -1 - n;
+                    text_buffer_.clear();
+                    n.write_string(text_buffer_);
+                    more_ = visitor.string_value(text_buffer_, semantic_tag::bigint, *this, ec);
+                    break;
+                }
+                case 0x15:
+                {
+                    read(bytes_buffer_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    more_ = visitor.byte_string_value(bytes_buffer_, semantic_tag::base64url, *this, ec);
+                    break;
+                }
+                case 0x16:
+                {
+                    read(bytes_buffer_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    more_ = visitor.byte_string_value(bytes_buffer_, semantic_tag::base64, *this, ec);
+                    break;
+                }
+                case 0x17:
+                {
+                    read(bytes_buffer_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    more_ = visitor.byte_string_value(bytes_buffer_, semantic_tag::base16, *this, ec);
+                    break;
+                }
+                case 0x40:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    uint8_t* data = reinterpret_cast<uint8_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size();
+                    more_ = visitor.typed_array(jsoncons::span<const uint8_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x44:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    uint8_t* data = reinterpret_cast<uint8_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size();
+                    more_ = visitor.typed_array(jsoncons::span<const uint8_t>(data,size), semantic_tag::clamped, *this, ec);
+                    break;
+                }
+                case 0x41:
+                case 0x45:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    uint16_t* data = reinterpret_cast<uint16_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<uint16_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const uint16_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x42:
+                case 0x46:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag);
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    uint32_t* data = reinterpret_cast<uint32_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<uint32_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const uint32_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x43:
+                case 0x47:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    uint64_t* data = reinterpret_cast<uint64_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<uint64_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const uint64_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x48:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    int8_t* data = reinterpret_cast<int8_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size();
+                    more_ = visitor.typed_array(jsoncons::span<const int8_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x49:
+                case 0x4d:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    int16_t* data = reinterpret_cast<int16_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<int16_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const int16_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x4a:
+                case 0x4e:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    int32_t* data = reinterpret_cast<int32_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<int32_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const int32_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x4b:
+                case 0x4f:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    int64_t* data = reinterpret_cast<int64_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<int64_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const int64_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x50:
+                case 0x54:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    uint16_t* data = reinterpret_cast<uint16_t*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<uint16_t>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(half_arg, jsoncons::span<const uint16_t>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x51:
+                case 0x55:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    float* data = reinterpret_cast<float*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<float>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const float>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                case 0x52:
+                case 0x56:
+                {
+                    typed_array_.clear();
+                    read(typed_array_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    const uint8_t tag = (uint8_t)item_tag_;
+                    jsoncons::endian e = get_typed_array_endianness(tag); 
+                    const size_t bytes_per_elem = get_typed_array_bytes_per_element(tag);
+
+                    double* data = reinterpret_cast<double*>(typed_array_.data());
+                    std::size_t size = typed_array_.size()/bytes_per_elem;
+
+                    if (e != jsoncons::endian::native)
+                    {
+                        for (std::size_t i = 0; i < size; ++i)
+                        {
+                            data[i] = binary::byte_swap<double>(data[i]);
+                        }
+                    }
+                    more_ = visitor.typed_array(jsoncons::span<const double>(data,size), semantic_tag::none, *this, ec);
+                    break;
+                }
+                default:
+                {
+                    read(bytes_buffer_,ec);
+                    if (ec)
+                    {
+                        more_ = false;
+                        return;
+                    }
+                    more_ = visitor.byte_string_value(bytes_buffer_, item_tag_, *this, ec);
+                    break;
+                }
+            }
+            other_tags_[item_tag] = false;
+        }
+        else
+        {
+            read(bytes_buffer_,ec);
+            if (ec)
+            {
+                return;
+            }
+            more_ = visitor.byte_string_value(bytes_buffer_, semantic_tag::none, *this, ec);
+        }
+    }
+
+    void produce_begin_multi_dim(json_visitor2& visitor, 
+                                 semantic_tag tag,
+                                 std::error_code& ec)
+    {
+        uint8_t b;
+        if (source_.read(&b, 1) == 0)
+        {
+            ec = cbor_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        jsoncons::cbor::detail::cbor_major_type major_type = get_major_type(b);
+        JSONCONS_ASSERT(major_type == jsoncons::cbor::detail::cbor_major_type::array);
+        uint8_t info = get_additional_information_value(b);
+       
+        read_shape(info, ec);   
+        if (ec)
+        {
+            return;
+        }
+
+        state_stack_.emplace_back(parse_mode::multi_dim, 0);
+        more_ = visitor.begin_multi_dim(shape_, tag, *this, ec);
+    }
+
+    void produce_end_multi_dim(json_visitor2& visitor, std::error_code& ec)
+    {
+        more_ = visitor.end_multi_dim(*this, ec);
+        state_stack_.pop_back();
+    }
+
+    void read_shape(uint8_t info, std::error_code& ec)
+    {
+        shape_.clear();
+        switch (info)
+        {
+            case jsoncons::cbor::detail::additional_info::indefinite_length:
+            {
+                while (true)
+                {
+                    auto c = source_.peek();
+                    if (c.eof)
+                    {
+                        ec = cbor_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (c.value == 0xff)
+                    {
+                        source_.ignore(1);
+                    }
+                    else
+                    {
+                        std::size_t dim = get_size(ec);
+                        if (!more_)
+                        {
+                            return;
+                        }
+                        shape_.push_back(dim);
+                    }
+                }
+                break;
+            }
+            default:
+            {
+                std::size_t size = get_size(ec);
+                if (!more_)
+                {
+                    return;
+                }
+                for (std::size_t i = 0; more_ && i < size; ++i)
+                {
+                    std::size_t dim = get_size(ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+                    shape_.push_back(dim);
+                }
+                break;
+            }
+        }
+    }
+};
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/cbor/cbor_reader.hpp b/include/jsoncons_ext/cbor/cbor_reader.hpp
new file mode 100644
index 0000000..a46a52e
--- /dev/null
+++ b/include/jsoncons_ext/cbor/cbor_reader.hpp
@@ -0,0 +1,116 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_CBOR_READER_HPP
+#define JSONCONS_CBOR_CBOR_READER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/cbor/cbor_encoder.hpp>
+#include <jsoncons_ext/cbor/cbor_error.hpp>
+#include <jsoncons_ext/cbor/cbor_detail.hpp>
+#include <jsoncons_ext/cbor/cbor_parser.hpp>
+
+namespace jsoncons { namespace cbor {
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_cbor_reader 
+{
+    using char_type = char;
+
+    basic_cbor_parser<Source,Allocator> parser_;
+    basic_json_visitor2_to_visitor_adaptor<char_type,Allocator> adaptor_;
+    json_visitor2& visitor_;
+public:
+    template <class Sourceable>
+    basic_cbor_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const Allocator alloc)
+       : basic_cbor_reader(std::forward<Sourceable>(source),
+                           visitor,
+                           cbor_decode_options(),
+                           alloc)
+    {
+    }
+
+    template <class Sourceable>
+    basic_cbor_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const cbor_decode_options& options = cbor_decode_options(),
+                      const Allocator alloc=Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         adaptor_(visitor, alloc), visitor_(adaptor_)
+    {
+    }
+    template <class Sourceable>
+    basic_cbor_reader(Sourceable&& source, 
+                      json_visitor2& visitor, 
+                      const Allocator alloc)
+       : basic_cbor_reader(std::forward<Sourceable>(source),
+                           visitor,
+                           cbor_decode_options(),
+                           alloc)
+    {
+    }
+
+    template <class Sourceable>
+    basic_cbor_reader(Sourceable&& source, 
+                      json_visitor2& visitor, 
+                      const cbor_decode_options& options = cbor_decode_options(),
+                      const Allocator alloc=Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         visitor_(visitor)
+    {
+    }
+
+    void read()
+    {
+        std::error_code ec;
+        read(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,line(),column()));
+        }
+    }
+
+    void read(std::error_code& ec)
+    {
+        parser_.reset();
+        parser_.parse(visitor_, ec);
+        if (ec)
+        {
+            return;
+        }
+    }
+
+    std::size_t line() const
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const
+    {
+        return parser_.column();
+    }
+};
+
+using cbor_stream_reader = basic_cbor_reader<jsoncons::binary_stream_source>;
+
+using cbor_bytes_reader = basic_cbor_reader<jsoncons::bytes_source>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+JSONCONS_DEPRECATED_MSG("Instead, use cbor_stream_reader") typedef cbor_stream_reader cbor_reader;
+JSONCONS_DEPRECATED_MSG("Instead, use cbor_bytes_reader") typedef cbor_bytes_reader cbor_buffer_reader;
+#endif
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/cbor/decode_cbor.hpp b/include/jsoncons_ext/cbor/decode_cbor.hpp
new file mode 100644
index 0000000..ab5c913
--- /dev/null
+++ b/include/jsoncons_ext/cbor/decode_cbor.hpp
@@ -0,0 +1,203 @@
+// Copyright 2017 Daniel Parkerstd
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_DECODE_CBOR_HPP
+#define JSONCONS_CBOR_DECODE_CBOR_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/json_filter.hpp>
+#include <jsoncons/decode_traits.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/cbor/cbor_reader.hpp>
+#include <jsoncons_ext/cbor/cbor_cursor.hpp>
+
+namespace jsoncons { 
+namespace cbor {
+
+    template<class T, class Source>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_cbor(const Source& v, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_cbor_reader<jsoncons::bytes_source> reader(v, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_cbor(const Source& v, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        basic_cbor_cursor<bytes_source> cursor(v, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_cbor(std::istream& is, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        cbor_stream_reader reader(is, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+     
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_cbor(std::istream& is, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        basic_cbor_cursor<binary_stream_source> cursor(is, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_cbor(InputIt first, InputIt last,
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_cbor_reader<binary_iterator_source<InputIt>> reader(binary_iterator_source<InputIt>(first, last), adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_cbor(InputIt first, InputIt last,
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        basic_cbor_cursor<binary_iterator_source<InputIt>> cursor(binary_iterator_source<InputIt>(first, last), options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    // With leading allocator parameter
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const Source& v, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_cbor_reader<jsoncons::bytes_source,TempAllocator> reader(v, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const Source& v, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        basic_cbor_cursor<bytes_source,TempAllocator> cursor(v, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                std::istream& is, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_cbor_reader<jsoncons::binary_stream_source,TempAllocator> reader(is, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                std::istream& is, 
+                const cbor_decode_options& options = cbor_decode_options())
+    {
+        basic_cbor_cursor<binary_stream_source,TempAllocator> cursor(is, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+} // namespace cbor
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/cbor/encode_cbor.hpp b/include/jsoncons_ext/cbor/encode_cbor.hpp
new file mode 100644
index 0000000..8576f1c
--- /dev/null
+++ b/include/jsoncons_ext/cbor/encode_cbor.hpp
@@ -0,0 +1,151 @@
+// Copyright 2017 Daniel Parkerstd
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CBOR_ENCODE_CBOR_HPP
+#define JSONCONS_CBOR_ENCODE_CBOR_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/json_filter.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/encode_traits.hpp>
+#include <jsoncons_ext/cbor/cbor_encoder.hpp>
+
+namespace jsoncons { 
+namespace cbor {
+
+    // to bytes 
+
+    template<class T, class Container>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_cbor(const T& j, 
+                Container& v, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_cbor_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_cbor(const T& val, Container& v, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        basic_cbor_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    // stream
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_cbor(const T& j, 
+                std::ostream& os, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        using char_type = typename T::char_type;
+        cbor_stream_encoder encoder(os, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_cbor(const T& val, 
+                std::ostream& os, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        cbor_stream_encoder encoder(os, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    // temp_allocator_arg
+
+    // to bytes 
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& j, 
+                Container& v, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_cbor_encoder<bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& val, 
+                Container& v, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        basic_cbor_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    // stream
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& j, 
+                std::ostream& os, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_cbor_encoder<binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_cbor(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                const T& val, 
+                std::ostream& os, 
+                const cbor_encode_options& options = cbor_encode_options())
+    {
+        std::error_code ec;
+        encode_cbor(temp_allocator_arg, temp_alloc, val, os, options, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+} // namespace cbor
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/csv/csv.hpp b/include/jsoncons_ext/csv/csv.hpp
new file mode 100644
index 0000000..9f8a9c5
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv.hpp
@@ -0,0 +1,17 @@
+/// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_HPP
+#define JSONCONS_CSV_CSV_HPP
+
+#include <jsoncons_ext/csv/csv_options.hpp>
+#include <jsoncons_ext/csv/csv_reader.hpp>
+#include <jsoncons_ext/csv/csv_encoder.hpp>
+#include <jsoncons_ext/csv/csv_cursor.hpp>
+#include <jsoncons_ext/csv/decode_csv.hpp>
+#include <jsoncons_ext/csv/encode_csv.hpp>
+
+#endif
diff --git a/include/jsoncons_ext/csv/csv_cursor.hpp b/include/jsoncons_ext/csv/csv_cursor.hpp
new file mode 100644
index 0000000..67d55a6
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_cursor.hpp
@@ -0,0 +1,358 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ 
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_CURSOR_HPP
+#define JSONCONS_CSV_CSV_CURSOR_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons_ext/csv/csv_parser.hpp>
+#include <jsoncons/staj_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/source_adaptor.hpp>
+
+namespace jsoncons { namespace csv {
+
+template<class CharT,class Source=jsoncons::stream_source<CharT>,class Allocator=std::allocator<char>>
+class basic_csv_cursor : public basic_staj_cursor<CharT>, private virtual ser_context
+{
+public:
+    using source_type = Source;
+    using char_type = CharT;
+    using allocator_type = Allocator;
+private:
+    static constexpr size_t default_max_buffer_size = 16384;
+
+    typedef typename std::allocator_traits<allocator_type>:: template rebind_alloc<CharT> char_allocator_type;
+
+    text_source_adaptor<Source> source_;
+    basic_csv_parser<CharT,Allocator> parser_;
+    basic_staj_visitor<CharT> cursor_visitor_;
+
+    // Noncopyable and nonmoveable
+    basic_csv_cursor(const basic_csv_cursor&) = delete;
+    basic_csv_cursor& operator=(const basic_csv_cursor&) = delete;
+
+public:
+    using string_view_type = jsoncons::basic_string_view<CharT>;
+
+    // Constructors that throw parse exceptions
+
+    template <class Sourceable>
+    basic_csv_cursor(Sourceable&& source, 
+                     const basic_csv_decode_options<CharT>& options = basic_csv_decode_options<CharT>(),
+                     std::function<bool(csv_errc,const ser_context&)> err_handler = default_csv_parsing(),
+                     const Allocator& alloc = Allocator(),
+                     typename std::enable_if<!std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type* = 0)
+       : source_(std::forward<Sourceable>(source)),
+         parser_(options,err_handler,alloc),
+         cursor_visitor_(accept_all)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    basic_csv_cursor(Sourceable&& source, 
+                     const basic_csv_decode_options<CharT>& options = basic_csv_decode_options<CharT>(),
+                     std::function<bool(csv_errc,const ser_context&)> err_handler = default_csv_parsing(),
+                     const Allocator& alloc = Allocator(),
+                     typename std::enable_if<std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type* = 0)
+       : source_(),
+         parser_(options,err_handler,alloc),
+         cursor_visitor_(accept_all)
+    {
+        jsoncons::basic_string_view<CharT> sv(std::forward<Sourceable>(source));
+        initialize_with_string_view(sv);
+    }
+
+
+    // Constructors that set parse error codes
+    template <class Sourceable>
+    basic_csv_cursor(Sourceable&& source, 
+                     std::error_code& ec)
+        : basic_csv_cursor(std::allocator_arg, Allocator(),
+                           std::forward<Sourceable>(source),
+                           basic_csv_decode_options<CharT>(),
+                           default_csv_parsing(),
+                           ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_csv_cursor(Sourceable&& source, 
+                     const basic_csv_decode_options<CharT>& options,
+                     std::error_code& ec)
+        : basic_csv_cursor(std::allocator_arg, Allocator(),
+                           std::forward<Sourceable>(source),
+                           options,
+                           default_csv_parsing(),
+                           ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_csv_cursor(Sourceable&& source, 
+                     const basic_csv_decode_options<CharT>& options,
+                     std::function<bool(csv_errc,const ser_context&)> err_handler,
+                     std::error_code& ec)
+        : basic_csv_cursor(std::allocator_arg, Allocator(),
+                           std::forward<Sourceable>(source),
+                           options,
+                           err_handler,
+                           ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_csv_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                     Sourceable&& source, 
+                     const basic_csv_decode_options<CharT>& options,
+                     std::function<bool(csv_errc,const ser_context&)> err_handler,
+                     std::error_code& ec,
+                     typename std::enable_if<!std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type* = 0)
+       : source_(std::forward<Sourceable>(source)),
+         parser_(options,err_handler,alloc),
+         cursor_visitor_(accept_all)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    template <class Sourceable>
+    basic_csv_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                     Sourceable&& source, 
+                     const basic_csv_decode_options<CharT>& options,
+                     std::function<bool(csv_errc,const ser_context&)> err_handler,
+                     std::error_code& ec,
+                     typename std::enable_if<std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type* = 0)
+       : source_(),
+         parser_(options,err_handler,alloc),
+         cursor_visitor_(accept_all)
+    {
+        jsoncons::basic_string_view<CharT> sv(std::forward<Sourceable>(source));
+        initialize_with_string_view(sv, ec);
+    }
+
+    template <class Sourceable>
+    typename std::enable_if<!std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type
+    reset(Sourceable&& source)
+    {
+        source_ = std::forward<Sourceable>(source);
+        parser_.reinitialize();
+        cursor_visitor_.reset();
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    typename std::enable_if<std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type
+    reset(Sourceable&& source)
+    {
+        source_ = {};
+        parser_.reinitialize();
+        cursor_visitor_.reset();
+        initialize_with_string_view(std::forward<Sourceable>(source));
+    }
+
+    template <class Sourceable>
+    typename std::enable_if<!std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type
+    reset(Sourceable&& source, std::error_code& ec)
+    {
+        source_ = std::forward<Sourceable>(source);
+        parser_.reinitialize();
+        cursor_visitor_.reset();
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    template <class Sourceable>
+    typename std::enable_if<std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type
+    reset(Sourceable&& source, std::error_code& ec)
+    {
+        source_ = {};
+        parser_.reinitialize();
+        initialize_with_string_view(std::forward<Sourceable>(source), ec);
+    }
+
+    bool done() const override
+    {
+        return parser_.done();
+    }
+
+    const basic_staj_event<CharT>& current() const override
+    {
+        return cursor_visitor_.event();
+    }
+
+    void read_to(basic_json_visitor<CharT>& visitor) override
+    {
+        std::error_code ec;
+        read_to(visitor, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void read_to(basic_json_visitor<CharT>& visitor,
+                std::error_code& ec) override
+    {
+        if (staj_to_saj_event(cursor_visitor_.event(), visitor, *this, ec))
+        {
+            read_next(visitor, ec);
+        }
+    }
+
+    void next() override
+    {
+        std::error_code ec;
+        next(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void next(std::error_code& ec) override
+    {
+        read_next(ec);
+    }
+
+    static bool accept_all(const basic_staj_event<CharT>&, const ser_context&) 
+    {
+        return true;
+    }
+
+    const ser_context& context() const override
+    {
+        return *this;
+    }
+
+    bool eof() const
+    {
+        return parser_.source_exhausted() && source_.eof();
+    }
+
+    std::size_t line() const override
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const override
+    {
+        return parser_.column();
+    }
+
+    friend
+    basic_staj_filter_view<CharT> operator|(basic_csv_cursor& cursor, 
+                                      std::function<bool(const basic_staj_event<CharT>&, const ser_context&)> pred)
+    {
+        return basic_staj_filter_view<CharT>(cursor, pred);
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<CharT>&)")
+    void read(basic_json_visitor<CharT>& visitor) 
+    {
+        read_to(visitor);
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<CharT>&, std::error_code&)")
+    void read(basic_json_visitor<CharT>& visitor,
+                 std::error_code& ec) 
+    {
+        read_to(visitor, ec);
+    }
+#endif
+private:
+
+    void initialize_with_string_view(string_view_type sv)
+    {
+        auto r = unicode_traits::detect_json_encoding(sv.data(), sv.size());
+        if (!(r.encoding == unicode_traits::encoding_kind::utf8 || r.encoding == unicode_traits::encoding_kind::undetected))
+        {
+            JSONCONS_THROW(ser_error(json_errc::illegal_unicode_character,parser_.line(),parser_.column()));
+        }
+        std::size_t offset = (r.ptr - sv.data());
+        parser_.update(sv.data()+offset,sv.size()-offset);
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    void initialize_with_string_view(string_view_type sv, std::error_code& ec)
+    {
+        auto r = unicode_traits::detect_encoding_from_bom(sv.data(), sv.size());
+        if (!(r.encoding == unicode_traits::encoding_kind::utf8 || r.encoding == unicode_traits::encoding_kind::undetected))
+        {
+            ec = json_errc::illegal_unicode_character;
+            return;
+        }
+        std::size_t offset = (r.ptr - sv.data());
+        parser_.update(sv.data()+offset,sv.size()-offset);
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    void read_next(std::error_code& ec)
+    {
+        read_next(cursor_visitor_, ec);
+    }
+
+    void read_next(basic_json_visitor<CharT>& visitor, std::error_code& ec)
+    {
+        parser_.restart();
+        while (!parser_.stopped())
+        {
+            if (parser_.source_exhausted())
+            {
+                auto s = source_.read_buffer(ec);
+                if (ec) return;
+                if (s.size() > 0)
+                {
+                    parser_.update(s.data(),s.size());
+                }
+            }
+            parser_.parse_some(visitor, ec);
+            if (ec) return;
+        }
+    }
+};
+
+using csv_stream_cursor = basic_csv_cursor<char,jsoncons::stream_source<char>>;
+using csv_string_cursor = basic_csv_cursor<char,jsoncons::string_source<char>>;
+using wcsv_stream_cursor = basic_csv_cursor<wchar_t,jsoncons::stream_source<wchar_t>>;
+using wcsv_string_cursor = basic_csv_cursor<wchar_t,jsoncons::string_source<wchar_t>>;
+
+using csv_cursor = basic_csv_cursor<char>;
+using wcsv_cursor = basic_csv_cursor<wchar_t>;
+
+}}
+
+#endif
+
diff --git a/include/jsoncons_ext/csv/csv_encoder.hpp b/include/jsoncons_ext/csv/csv_encoder.hpp
new file mode 100644
index 0000000..49c1a3d
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_encoder.hpp
@@ -0,0 +1,954 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_ENCODER_HPP
+#define JSONCONS_CSV_CSV_ENCODER_HPP
+
+#include <array> // std::array
+#include <string>
+#include <vector>
+#include <ostream>
+#include <utility> // std::move
+#include <unordered_map> // std::unordered_map
+#include <memory> // std::allocator
+#include <limits> // std::numeric_limits
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/detail/write_number.hpp>
+#include <jsoncons_ext/csv/csv_options.hpp>
+#include <jsoncons/sink.hpp>
+
+namespace jsoncons { namespace csv {
+
+template<class CharT,class Sink=jsoncons::stream_sink<CharT>,class Allocator=std::allocator<char>>
+class basic_csv_encoder final : public basic_json_visitor<CharT>
+{
+public:
+    using char_type = CharT;
+    using typename basic_json_visitor<CharT>::string_view_type;
+    using sink_type = Sink;
+
+    using allocator_type = Allocator;
+    using char_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<CharT>;
+    using string_type = std::basic_string<CharT, std::char_traits<CharT>, char_allocator_type>;
+    using string_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<string_type>;
+    using string_string_allocator_type = typename std::allocator_traits<allocator_type>:: template rebind_alloc<std::pair<const string_type,string_type>>;
+
+private:
+    static jsoncons::basic_string_view<CharT> null_constant()
+    {
+        static jsoncons::basic_string_view<CharT> k = JSONCONS_STRING_VIEW_CONSTANT(CharT,"null");
+        return k;
+    }
+    static jsoncons::basic_string_view<CharT> true_constant()
+    {
+        static jsoncons::basic_string_view<CharT> k = JSONCONS_STRING_VIEW_CONSTANT(CharT,"true");
+        return k;
+    }
+    static jsoncons::basic_string_view<CharT> false_constant()
+    {
+        static jsoncons::basic_string_view<CharT> k = JSONCONS_STRING_VIEW_CONSTANT(CharT,"false");
+        return k;
+    }
+
+    enum class stack_item_kind
+    {
+        row_mapping,
+        column_mapping,
+        object,
+        row,
+        column,
+        object_multi_valued_field,
+        row_multi_valued_field,
+        column_multi_valued_field
+    };
+
+    struct stack_item
+    {
+        stack_item_kind item_kind_;
+        std::size_t count_;
+
+        stack_item(stack_item_kind item_kind) noexcept
+           : item_kind_(item_kind), count_(0)
+        {
+        }
+
+        bool is_object() const
+        {
+            return item_kind_ == stack_item_kind::object;
+        }
+
+        stack_item_kind item_kind() const
+        {
+            return item_kind_;
+        }
+    };
+
+    Sink sink_;
+    const basic_csv_encode_options<CharT> options_;
+    allocator_type alloc_;
+
+    std::vector<stack_item> stack_;
+    jsoncons::detail::write_double fp_;
+    std::vector<string_type,string_allocator_type> strings_buffer_;
+
+    std::unordered_map<string_type,string_type, std::hash<string_type>,std::equal_to<string_type>,string_string_allocator_type> buffered_line_;
+    string_type name_;
+    std::size_t column_index_;
+    std::vector<std::size_t> row_counts_;
+
+    // Noncopyable and nonmoveable
+    basic_csv_encoder(const basic_csv_encoder&) = delete;
+    basic_csv_encoder& operator=(const basic_csv_encoder&) = delete;
+public:
+    basic_csv_encoder(Sink&& sink, 
+                      const Allocator& alloc = Allocator())
+       : basic_csv_encoder(std::forward<Sink>(sink), basic_csv_encode_options<CharT>(), alloc)
+    {
+    }
+
+    basic_csv_encoder(Sink&& sink,
+                      const basic_csv_encode_options<CharT>& options, 
+                      const Allocator& alloc = Allocator())
+      : sink_(std::forward<Sink>(sink)),
+        options_(options),
+        alloc_(alloc),
+        stack_(),
+        fp_(options.float_format(), options.precision()),
+        column_index_(0)
+    {
+        jsoncons::csv::detail::parse_column_names(options.column_names(), strings_buffer_);
+    }
+
+    ~basic_csv_encoder() noexcept
+    {
+        JSONCONS_TRY
+        {
+            sink_.flush();
+        }
+        JSONCONS_CATCH(...)
+        {
+        }
+    }
+
+    void reset()
+    {
+        stack_.clear();
+        strings_buffer_.clear();
+        buffered_line_.clear();
+        name_.clear();
+        column_index_ = 0;
+        row_counts_.clear();
+    }
+
+    void reset(Sink&& sink)
+    {
+        sink_ = std::move(sink);
+        reset();
+    }
+
+private:
+
+    template<class AnyWriter>
+    void escape_string(const CharT* s,
+                       std::size_t length,
+                       CharT quote_char, CharT quote_escape_char,
+                       AnyWriter& sink)
+    {
+        const CharT* begin = s;
+        const CharT* end = s + length;
+        for (const CharT* it = begin; it != end; ++it)
+        {
+            CharT c = *it;
+            if (c == quote_char)
+            {
+                sink.push_back(quote_escape_char); 
+                sink.push_back(quote_char);
+            }
+            else
+            {
+                sink.push_back(c);
+            }
+        }
+    }
+
+    void visit_flush() override
+    {
+        sink_.flush();
+    }
+
+    bool visit_begin_object(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            stack_.emplace_back(stack_item_kind::column_mapping);
+            return true;
+        }
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::row_mapping:
+                stack_.emplace_back(stack_item_kind::object);
+                return true;
+            default: // error
+                ec = csv_errc::source_error;
+                return false;
+        }
+    }
+
+    bool visit_end_object(const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+                if (stack_[0].count_ == 0)
+                {
+                    for (std::size_t i = 0; i < strings_buffer_.size(); ++i)
+                    {
+                        if (i > 0)
+                        {
+                            sink_.push_back(options_.field_delimiter());
+                        }
+                        sink_.append(strings_buffer_[i].data(),
+                                      strings_buffer_[i].length());
+                    }
+                    sink_.append(options_.line_delimiter().data(),
+                                  options_.line_delimiter().length());
+                }
+                for (std::size_t i = 0; i < strings_buffer_.size(); ++i)
+                {
+                    if (i > 0)
+                    {
+                        sink_.push_back(options_.field_delimiter());
+                    }
+                    auto it = buffered_line_.find(strings_buffer_[i]);
+                    if (it != buffered_line_.end())
+                    {
+                        sink_.append(it->second.data(),it->second.length());
+                        it->second.clear();
+                    }
+                }
+                sink_.append(options_.line_delimiter().data(), options_.line_delimiter().length());
+                break;
+            case stack_item_kind::column_mapping:
+             {
+                 for (const auto& item : strings_buffer_)
+                 {
+                     sink_.append(item.data(), item.size());
+                     sink_.append(options_.line_delimiter().data(), options_.line_delimiter().length());
+                 }
+                 break;
+             }
+            default:
+                break;
+        }
+        stack_.pop_back();
+        if (!stack_.empty())
+        {
+            end_value();
+        }
+        return true;
+    }
+
+    bool visit_begin_array(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (stack_.empty())
+        {
+            stack_.emplace_back(stack_item_kind::row_mapping);
+            return true;
+        }
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::row_mapping:
+                stack_.emplace_back(stack_item_kind::row);
+                if (stack_[0].count_ == 0)
+                {
+                    for (std::size_t i = 0; i < strings_buffer_.size(); ++i)
+                    {
+                        if (i > 0)
+                        {
+                            sink_.push_back(options_.field_delimiter());
+                        }
+                        sink_.append(strings_buffer_[i].data(),strings_buffer_[i].length());
+                    }
+                    if (strings_buffer_.size() > 0)
+                    {
+                        sink_.append(options_.line_delimiter().data(),
+                                      options_.line_delimiter().length());
+                    }
+                }
+                return true;
+            case stack_item_kind::object:
+                stack_.emplace_back(stack_item_kind::object_multi_valued_field);
+                return true;
+            case stack_item_kind::column_mapping:
+                stack_.emplace_back(stack_item_kind::column);
+                row_counts_.push_back(1);
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                return true;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }                
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                begin_value(bo);
+                stack_.emplace_back(stack_item_kind::column_multi_valued_field);
+                return true;
+            }
+            case stack_item_kind::row:
+                begin_value(sink_);
+                stack_.emplace_back(stack_item_kind::row_multi_valued_field);
+                return true;
+            default: // error
+                ec = csv_errc::source_error;
+                return false;
+        }
+    }
+
+    bool visit_end_array(const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::row:
+                sink_.append(options_.line_delimiter().data(),
+                              options_.line_delimiter().length());
+                break;
+            case stack_item_kind::column:
+                ++column_index_;
+                break;
+            default:
+                break;
+        }
+        stack_.pop_back();
+
+        if (!stack_.empty())
+        {
+            end_value();
+        }
+        return true;
+    }
+
+    bool visit_key(const string_view_type& name, const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            {
+                name_ = string_type(name);
+                buffered_line_[string_type(name)] = std::basic_string<CharT>();
+                if (stack_[0].count_ == 0 && options_.column_names().size() == 0)
+                {
+                    strings_buffer_.emplace_back(name);
+                }
+                break;
+            }
+            case stack_item_kind::column_mapping:
+            {
+                if (strings_buffer_.empty())
+                {
+                    strings_buffer_.emplace_back(name);
+                }
+                else
+                {
+                    strings_buffer_[0].push_back(options_.field_delimiter());
+                    strings_buffer_[0].append(string_type(name));
+                }
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    bool visit_null(semantic_tag, const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            case stack_item_kind::object_multi_valued_field:
+            {
+                auto it = buffered_line_.find(name_);
+                if (it != buffered_line_.end())
+                {
+                    std::basic_string<CharT> s;
+                    jsoncons::string_sink<std::basic_string<CharT>> bo(s);
+                    write_null_value(bo);
+                    bo.flush();
+                    if (!it->second.empty() && options_.subfield_delimiter() != char_type())
+                    {
+                        it->second.push_back(options_.subfield_delimiter());
+                    }
+                    it->second.append(s);
+                }
+                break;
+            }
+            case stack_item_kind::row:
+            case stack_item_kind::row_multi_valued_field:
+                write_null_value(sink_);
+                break;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_null_value(bo);
+                break;
+            }
+            case stack_item_kind::column_multi_valued_field:
+            {
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_null_value(bo);
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    bool visit_string(const string_view_type& sv, semantic_tag, const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            case stack_item_kind::object_multi_valued_field:
+            {
+                auto it = buffered_line_.find(name_);
+                if (it != buffered_line_.end())
+                {
+                    std::basic_string<CharT> s;
+                    jsoncons::string_sink<std::basic_string<CharT>> bo(s);
+                    write_string_value(sv,bo);
+                    bo.flush();
+                    if (!it->second.empty() && options_.subfield_delimiter() != char_type())
+                    {
+                        it->second.push_back(options_.subfield_delimiter());
+                    }
+                    it->second.append(s);
+                }
+                break;
+            }
+            case stack_item_kind::row:
+            case stack_item_kind::row_multi_valued_field:
+                write_string_value(sv,sink_);
+                break;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_string_value(sv,bo);
+                break;
+            }
+            case stack_item_kind::column_multi_valued_field:
+            {
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_string_value(sv,bo);
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    bool visit_byte_string(const byte_string_view& b, 
+                              semantic_tag tag, 
+                              const ser_context& context,
+                              std::error_code& ec) override
+    {
+        byte_string_chars_format encoding_hint;
+        switch (tag)
+        {
+            case semantic_tag::base16:
+                encoding_hint = byte_string_chars_format::base16;
+                break;
+            case semantic_tag::base64:
+                encoding_hint = byte_string_chars_format::base64;
+                break;
+            case semantic_tag::base64url:
+                encoding_hint = byte_string_chars_format::base64url;
+                break;
+            default:
+                encoding_hint = byte_string_chars_format::none;
+                break;
+        }
+        byte_string_chars_format format = jsoncons::detail::resolve_byte_string_chars_format(encoding_hint,byte_string_chars_format::none,byte_string_chars_format::base64url);
+
+        std::basic_string<CharT> s;
+        switch (format)
+        {
+            case byte_string_chars_format::base16:
+            {
+                encode_base16(b.begin(),b.end(),s);
+                visit_string(s, semantic_tag::none, context, ec);
+                break;
+            }
+            case byte_string_chars_format::base64:
+            {
+                encode_base64(b.begin(),b.end(),s);
+                visit_string(s, semantic_tag::none, context, ec);
+                break;
+            }
+            case byte_string_chars_format::base64url:
+            {
+                encode_base64url(b.begin(),b.end(),s);
+                visit_string(s, semantic_tag::none, context, ec);
+                break;
+            }
+            default:
+            {
+                JSONCONS_UNREACHABLE();
+            }
+        }
+
+        return true;
+    }
+
+    bool visit_double(double val, 
+                         semantic_tag, 
+                         const ser_context& context,
+                         std::error_code& ec) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            case stack_item_kind::object_multi_valued_field:
+            {
+                auto it = buffered_line_.find(name_);
+                if (it != buffered_line_.end())
+                {
+                    std::basic_string<CharT> s;
+                    jsoncons::string_sink<std::basic_string<CharT>> bo(s);
+                    write_double_value(val, context, bo, ec);
+                    bo.flush();
+                    if (!it->second.empty() && options_.subfield_delimiter() != char_type())
+                    {
+                        it->second.push_back(options_.subfield_delimiter());
+                    }
+                    it->second.append(s);
+                }
+                break;
+            }
+            case stack_item_kind::row:
+            case stack_item_kind::row_multi_valued_field:
+                write_double_value(val, context, sink_, ec);
+                break;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_double_value(val, context, bo, ec);
+                break;
+            }
+            case stack_item_kind::column_multi_valued_field:
+            {
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_double_value(val, context, bo, ec);
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    bool visit_int64(int64_t val, 
+                        semantic_tag, 
+                        const ser_context&,
+                        std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            case stack_item_kind::object_multi_valued_field:
+            {
+                auto it = buffered_line_.find(name_);
+                if (it != buffered_line_.end())
+                {
+                    std::basic_string<CharT> s;
+                    jsoncons::string_sink<std::basic_string<CharT>> bo(s);
+                    write_int64_value(val,bo);
+                    bo.flush();
+                    if (!it->second.empty() && options_.subfield_delimiter() != char_type())
+                    {
+                        it->second.push_back(options_.subfield_delimiter());
+                    }
+                    it->second.append(s);
+                }
+                break;
+            }
+            case stack_item_kind::row:
+            case stack_item_kind::row_multi_valued_field:
+                write_int64_value(val,sink_);
+                break;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_int64_value(val, bo);
+                break;
+            }
+            case stack_item_kind::column_multi_valued_field:
+            {
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_int64_value(val, bo);
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    bool visit_uint64(uint64_t val, 
+                      semantic_tag, 
+                      const ser_context&,
+                      std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            case stack_item_kind::object_multi_valued_field:
+            {
+                auto it = buffered_line_.find(name_);
+                if (it != buffered_line_.end())
+                {
+                    std::basic_string<CharT> s;
+                    jsoncons::string_sink<std::basic_string<CharT>> bo(s);
+                    write_uint64_value(val, bo);
+                    bo.flush();
+                    if (!it->second.empty() && options_.subfield_delimiter() != char_type())
+                    {
+                        it->second.push_back(options_.subfield_delimiter());
+                    }
+                    it->second.append(s);
+                }
+                break;
+            }
+            case stack_item_kind::row:
+            case stack_item_kind::row_multi_valued_field:
+                write_uint64_value(val,sink_);
+                break;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_uint64_value(val, bo);
+                break;
+            }
+            case stack_item_kind::column_multi_valued_field:
+            {
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_uint64_value(val, bo);
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    bool visit_bool(bool val, semantic_tag, const ser_context&, std::error_code&) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::object:
+            case stack_item_kind::object_multi_valued_field:
+            {
+                auto it = buffered_line_.find(name_);
+                if (it != buffered_line_.end())
+                {
+                    std::basic_string<CharT> s;
+                    jsoncons::string_sink<std::basic_string<CharT>> bo(s);
+                    write_bool_value(val,bo);
+                    bo.flush();
+                    if (!it->second.empty() && options_.subfield_delimiter() != char_type())
+                    {
+                        it->second.push_back(options_.subfield_delimiter());
+                    }
+                    it->second.append(s);
+                }
+                break;
+            }
+            case stack_item_kind::row:
+            case stack_item_kind::row_multi_valued_field:
+                write_bool_value(val,sink_);
+                break;
+            case stack_item_kind::column:
+            {
+                if (strings_buffer_.size() <= row_counts_.back())
+                {
+                    strings_buffer_.emplace_back();
+                }
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_bool_value(val, bo);
+                break;
+            }
+            case stack_item_kind::column_multi_valued_field:
+            {
+                jsoncons::string_sink<std::basic_string<CharT>> bo(strings_buffer_[row_counts_.back()]);
+                write_bool_value(val, bo);
+                break;
+            }
+            default:
+                break;
+        }
+        return true;
+    }
+
+    template <class AnyWriter>
+    bool do_string_value(const CharT* s, std::size_t length, AnyWriter& sink)
+    {
+        bool quote = false;
+        if (options_.quote_style() == quote_style_kind::all || options_.quote_style() == quote_style_kind::nonnumeric ||
+            (options_.quote_style() == quote_style_kind::minimal &&
+            (std::char_traits<CharT>::find(s, length, options_.field_delimiter()) != nullptr || std::char_traits<CharT>::find(s, length, options_.quote_char()) != nullptr)))
+        {
+            quote = true;
+            sink.push_back(options_.quote_char());
+        }
+        escape_string(s, length, options_.quote_char(), options_.quote_escape_char(), sink);
+        if (quote)
+        {
+            sink.push_back(options_.quote_char());
+        }
+
+        return true;
+    }
+
+    template <class AnyWriter>
+    void write_string_value(const string_view_type& value, AnyWriter& sink)
+    {
+        begin_value(sink);
+        do_string_value(value.data(),value.length(),sink);
+        end_value();
+    }
+
+    template <class AnyWriter>
+    void write_double_value(double val, const ser_context& context, AnyWriter& sink, std::error_code& ec)
+    {
+        begin_value(sink);
+
+        if (!std::isfinite(val))
+        {
+            if ((std::isnan)(val))
+            {
+                if (options_.enable_nan_to_num())
+                {
+                    sink.append(options_.nan_to_num().data(), options_.nan_to_num().length());
+                }
+                else if (options_.enable_nan_to_str())
+                {
+                    visit_string(options_.nan_to_str(), semantic_tag::none, context, ec);
+                }
+                else
+                {
+                    sink.append(null_constant().data(), null_constant().size());
+                }
+            }
+            else if (val == std::numeric_limits<double>::infinity())
+            {
+                if (options_.enable_inf_to_num())
+                {
+                    sink.append(options_.inf_to_num().data(), options_.inf_to_num().length());
+                }
+                else if (options_.enable_inf_to_str())
+                {
+                    visit_string(options_.inf_to_str(), semantic_tag::none, context, ec);
+                }
+                else
+                {
+                    sink.append(null_constant().data(), null_constant().size());
+                }
+            }
+            else
+            {
+                if (options_.enable_neginf_to_num())
+                {
+                    sink.append(options_.neginf_to_num().data(), options_.neginf_to_num().length());
+                }
+                else if (options_.enable_neginf_to_str())
+                {
+                    visit_string(options_.neginf_to_str(), semantic_tag::none, context, ec);
+                }
+                else
+                {
+                    sink.append(null_constant().data(), null_constant().size());
+                }
+            }
+        }
+        else
+        {
+            fp_(val, sink);
+        }
+
+        end_value();
+
+    }
+
+    template <class AnyWriter>
+    void write_int64_value(int64_t val, AnyWriter& sink)
+    {
+        begin_value(sink);
+
+        jsoncons::detail::from_integer(val,sink);
+
+        end_value();
+    }
+
+    template <class AnyWriter>
+    void write_uint64_value(uint64_t val, AnyWriter& sink)
+    {
+        begin_value(sink);
+
+        jsoncons::detail::from_integer(val,sink);
+
+        end_value();
+    }
+
+    template <class AnyWriter>
+    void write_bool_value(bool val, AnyWriter& sink) 
+    {
+        begin_value(sink);
+
+        if (val)
+        {
+            sink.append(true_constant().data(), true_constant().size());
+        }
+        else
+        {
+            sink.append(false_constant().data(), false_constant().size());
+        }
+
+        end_value();
+    }
+ 
+    template <class AnyWriter>
+    bool write_null_value(AnyWriter& sink) 
+    {
+        begin_value(sink);
+        sink.append(null_constant().data(), null_constant().size());
+        end_value();
+        return true;
+    }
+
+    template <class AnyWriter>
+    void begin_value(AnyWriter& sink)
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch (stack_.back().item_kind_)
+        {
+            case stack_item_kind::row:
+                if (stack_.back().count_ > 0)
+                {
+                    sink.push_back(options_.field_delimiter());
+                }
+                break;
+            case stack_item_kind::column:
+            {
+                if (row_counts_.size() >= 3)
+                {
+                    for (std::size_t i = row_counts_.size()-2; i-- > 0;)
+                    {
+                        if (row_counts_[i] <= row_counts_.back())
+                        {
+                            sink.push_back(options_.field_delimiter());
+                        }
+                        else
+                        {
+                            break;
+                        }
+                    }
+                }
+                if (column_index_ > 0)
+                {
+                    sink.push_back(options_.field_delimiter());
+                }
+                break;
+            }
+            case stack_item_kind::row_multi_valued_field:
+            case stack_item_kind::column_multi_valued_field:
+                if (stack_.back().count_ > 0 && options_.subfield_delimiter() != char_type())
+                {
+                    sink.push_back(options_.subfield_delimiter());
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    void end_value()
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        switch(stack_.back().item_kind_)
+        {
+            case stack_item_kind::row:
+            {
+                ++stack_.back().count_;
+                break;
+            }
+            case stack_item_kind::column:
+            {
+                ++row_counts_.back();
+                break;
+            }
+            default:
+                ++stack_.back().count_;
+                break;
+        }
+    }
+};
+
+using csv_stream_encoder = basic_csv_encoder<char>;
+using csv_string_encoder = basic_csv_encoder<char,jsoncons::string_sink<std::string>>;
+using csv_wstream_encoder = basic_csv_encoder<wchar_t>;
+using wcsv_string_encoder = basic_csv_encoder<wchar_t,jsoncons::string_sink<std::wstring>>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+template<class CharT, class Sink = jsoncons::stream_sink<CharT>, class Allocator = std::allocator<CharT>>
+using basic_csv_serializer = basic_csv_encoder<CharT,Sink,Allocator>;
+
+JSONCONS_DEPRECATED_MSG("Instead, use csv_stream_encoder") typedef csv_stream_encoder csv_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use csv_string_encoder") typedef csv_string_encoder csv_string_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use csv_stream_encoder") typedef csv_stream_encoder csv_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use csv_string_encoder") typedef csv_string_encoder csv_string_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use csv_stream_encoder") typedef csv_stream_encoder csv_encoder;
+JSONCONS_DEPRECATED_MSG("Instead, use wcsv_stream_encoder") typedef csv_stream_encoder wcsv_encoder;
+#endif
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/csv/csv_error.hpp b/include/jsoncons_ext/csv/csv_error.hpp
new file mode 100644
index 0000000..30255dd
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_error.hpp
@@ -0,0 +1,85 @@
+/// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_ERROR_HPP
+#define JSONCONS_CSV_CSV_ERROR_HPP
+
+#include <system_error>
+#include <jsoncons/json_exception.hpp>
+
+namespace jsoncons { namespace csv {
+
+    enum class csv_errc : int
+    {
+        success = 0,
+        unexpected_eof = 1,
+        source_error,
+        expected_quote,
+        syntax_error,
+        invalid_parse_state,
+        invalid_escaped_char,
+        unexpected_char_between_fields
+    };
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+JSONCONS_DEPRECATED_MSG("Instead, use csv_errc") typedef csv_errc csv_parser_errc;
+#endif
+
+class csv_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/csv";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<csv_errc>(ev))
+        {
+            case csv_errc::unexpected_eof:
+                return "Unexpected end of file";
+            case csv_errc::source_error:
+                return "Source error";
+            case csv_errc::expected_quote:
+                return "Expected quote character";
+            case csv_errc::syntax_error:
+                return "CSV syntax error";
+            case csv_errc::invalid_parse_state:
+                return "Invalid CSV parser state";
+            case csv_errc::invalid_escaped_char:
+                return "Invalid character following quote escape character";
+            case csv_errc::unexpected_char_between_fields:
+                return "Unexpected character between fields";
+            default:
+                return "Unknown CSV parser error";
+        }
+    }
+};
+
+inline
+const std::error_category& csv_error_category()
+{
+  static csv_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(csv_errc result)
+{
+    return std::error_code(static_cast<int>(result),csv_error_category());
+}
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::csv::csv_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/csv/csv_options.hpp b/include/jsoncons_ext/csv/csv_options.hpp
new file mode 100644
index 0000000..8bd2e22
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_options.hpp
@@ -0,0 +1,973 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_OPTIONS_HPP
+#define JSONCONS_CSV_CSV_OPTIONS_HPP
+
+#include <string>
+#include <vector>
+#include <utility> // std::pair
+#include <unordered_map> // std::unordered_map
+#include <map>
+#include <limits> // std::numeric_limits
+#include <cwchar>
+#include <jsoncons/json_options.hpp>
+
+namespace jsoncons { namespace csv {
+
+enum class csv_column_type : uint8_t 
+{
+    string_t,integer_t,float_t,boolean_t,repeat_t
+};
+
+enum class quote_style_kind : uint8_t 
+{
+    minimal,all,nonnumeric,none
+};
+
+enum class csv_mapping_kind : uint8_t 
+{
+    n_rows = 1, 
+    n_objects, 
+    m_columns
+};
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+using mapping_kind = csv_mapping_kind;
+JSONCONS_DEPRECATED_MSG("Instead, use quote_style_kind") typedef quote_style_kind quote_styles;
+JSONCONS_DEPRECATED_MSG("Instead, use quote_style_kind") typedef quote_style_kind quote_style_type;
+JSONCONS_DEPRECATED_MSG("Instead, use csv_mapping_kind") typedef csv_mapping_kind mapping_type;
+#endif
+
+enum class column_state {sequence,label};
+
+struct csv_type_info
+{
+    csv_type_info() = default;
+    csv_type_info(const csv_type_info&) = default;
+    csv_type_info(csv_type_info&&) = default;
+
+    csv_type_info(csv_column_type ctype, std::size_t lev, std::size_t repcount = 0) noexcept
+    {
+        col_type = ctype;
+        level = lev;
+        rep_count = repcount;
+    }
+
+    csv_column_type col_type;
+    std::size_t level;
+    std::size_t rep_count;
+};
+
+namespace detail {
+
+template <class CharT,class Container>
+void parse_column_names(const std::basic_string<CharT>& names, 
+                        Container& cont)
+{
+    column_state state = column_state::sequence;
+    typename Container::value_type buffer(cont.get_allocator());
+
+    auto p = names.begin();
+    while (p != names.end())
+    {
+        switch (state)
+        {
+            case column_state::sequence:
+            {
+                switch (*p)
+                {
+                    case ' ': case '\t':case '\r': case '\n':
+                        ++p;
+                        break;
+                    default:
+                        buffer.clear();
+                        state = column_state::label;
+                        break;
+                }
+                break;
+            }
+            case column_state::label:
+            {
+                switch (*p)
+                {
+                case ',':
+                    cont.push_back(buffer);
+                    buffer.clear();
+                    ++p;
+                    state = column_state::sequence;
+                    break;
+                default:
+                    buffer.push_back(*p);
+                    ++p;
+                    break;
+                }
+                break;
+            }
+        }
+    }
+    if (state == column_state::label)
+    {
+        cont.push_back(buffer);
+        buffer.clear();
+    }
+}
+
+template <class CharT,class Container>
+void parse_column_types(const std::basic_string<CharT>& types, 
+                        Container& column_types)
+{
+    const std::map<jsoncons::basic_string_view<CharT>,csv_column_type> type_dictionary =
+    {
+
+        {JSONCONS_STRING_VIEW_CONSTANT(CharT,"string"),csv_column_type::string_t},
+        {JSONCONS_STRING_VIEW_CONSTANT(CharT,"integer"),csv_column_type::integer_t},
+        {JSONCONS_STRING_VIEW_CONSTANT(CharT,"float"),csv_column_type::float_t},
+        {JSONCONS_STRING_VIEW_CONSTANT(CharT,"boolean"),csv_column_type::boolean_t}
+    };
+
+    column_state state = column_state::sequence;
+    int depth = 0;
+    std::basic_string<CharT> buffer;
+
+    auto p = types.begin();
+    while (p != types.end())
+    {
+        switch (state)
+        {
+            case column_state::sequence:
+            {
+                switch (*p)
+                {
+                case ' ': case '\t':case '\r': case '\n':
+                    ++p;
+                    break;
+                case '[':
+                    ++depth;
+                    ++p;
+                    break;
+                case ']':
+                    JSONCONS_ASSERT(depth > 0);
+                    --depth;
+                    ++p;
+                    break;
+                case '*':
+                    {
+                        JSONCONS_ASSERT(column_types.size() != 0);
+                        std::size_t offset = 0;
+                        std::size_t level = column_types.size() > 0 ? column_types.back().level: 0;
+                        if (level > 0)
+                        {
+                            for (auto it = column_types.rbegin();
+                                 it != column_types.rend() && level == it->level;
+                                 ++it)
+                            {
+                                ++offset;
+                            }
+                        }
+                        else
+                        {
+                            offset = 1;
+                        }
+                        column_types.emplace_back(csv_column_type::repeat_t,depth,offset);
+                        ++p;
+                        break;
+                    }
+                default:
+                    buffer.clear();
+                    state = column_state::label;
+                    break;
+                }
+                break;
+            }
+            case column_state::label:
+            {
+                switch (*p)
+                {
+                    case '*':
+                    {
+                        auto it = type_dictionary.find(buffer);
+                        if (it != type_dictionary.end())
+                        {
+                            column_types.emplace_back(it->second,depth);
+                            buffer.clear();
+                        }
+                        else
+                        {
+                            JSONCONS_ASSERT(false);
+                        }
+                        state = column_state::sequence;
+                        break;
+                    }
+                    case ',':
+                    {
+                        auto it = type_dictionary.find(buffer);
+                        if (it != type_dictionary.end())
+                        {
+                            column_types.emplace_back(it->second,depth);
+                            buffer.clear();
+                        }
+                        else
+                        {
+                            JSONCONS_ASSERT(false);
+                        }
+                        ++p;
+                        state = column_state::sequence;
+                        break;
+                    }
+                    case ']':
+                    {
+                        JSONCONS_ASSERT(depth > 0);
+                        auto it = type_dictionary.find(buffer);
+                        if (it != type_dictionary.end())
+                        {
+                            column_types.emplace_back(it->second,depth);
+                            buffer.clear();
+                        }
+                        else
+                        {
+                            JSONCONS_ASSERT(false);
+                        }
+                        --depth;
+                        ++p;
+                        state = column_state::sequence;
+                        break;
+                    }
+                    default:
+                    {
+                        buffer.push_back(*p);
+                        ++p;
+                        break;
+                    }
+                }
+                break;
+            }
+        }
+    }
+    if (state == column_state::label)
+    {
+        auto it = type_dictionary.find(buffer);
+        if (it != type_dictionary.end())
+        {
+            column_types.emplace_back(it->second,depth);
+            buffer.clear();
+        }
+        else
+        {
+            JSONCONS_ASSERT(false);
+        }
+    }
+}
+
+} // detail
+
+template <class CharT>
+class basic_csv_options;
+
+template <class CharT>
+class basic_csv_options_common 
+{
+    friend class basic_csv_options<CharT>;
+public:
+    using char_type = CharT;
+    using string_type = std::basic_string<CharT>;
+private:
+    char_type field_delimiter_;
+    char_type quote_char_;
+    char_type quote_escape_char_;
+    char_type subfield_delimiter_;
+
+    bool enable_nan_to_num_:1;
+    bool enable_inf_to_num_:1;
+    bool enable_neginf_to_num_:1;
+    bool enable_nan_to_str_:1;
+    bool enable_inf_to_str_:1;
+    bool enable_neginf_to_str_:1;
+    bool enable_str_to_nan_:1;
+    bool enable_str_to_inf_:1;
+    bool enable_str_to_neginf_:1;
+
+    string_type nan_to_num_;
+    string_type inf_to_num_;
+    string_type neginf_to_num_;
+    string_type nan_to_str_;
+    string_type inf_to_str_;
+    string_type neginf_to_str_;
+    string_type column_names_;
+
+protected:
+    basic_csv_options_common()
+      : field_delimiter_(','),
+        quote_char_('\"'),
+        quote_escape_char_('\"'),
+        subfield_delimiter_(char_type()),
+        enable_nan_to_num_(false),
+        enable_inf_to_num_(false),
+        enable_neginf_to_num_(false),
+        enable_nan_to_str_(false),
+        enable_inf_to_str_(false),
+        enable_neginf_to_str_(false),
+        enable_str_to_nan_(false),
+        enable_str_to_inf_(false),
+        enable_str_to_neginf_(false)
+    {
+    }
+
+    basic_csv_options_common(const basic_csv_options_common&) = default;
+    basic_csv_options_common& operator=(const basic_csv_options_common&) = default;
+
+    virtual ~basic_csv_options_common() noexcept = default;
+public:
+
+    char_type field_delimiter() const 
+    {
+        return field_delimiter_;
+    }
+
+    const char_type subfield_delimiter() const 
+    {
+        return subfield_delimiter_;
+    }
+
+    char_type quote_char() const 
+    {
+        return quote_char_;
+    }
+
+    char_type quote_escape_char() const 
+    {
+        return quote_escape_char_;
+    }
+
+    string_type column_names() const 
+    {
+        return column_names_;
+    }
+
+    bool enable_nan_to_num() const
+    {
+        return enable_nan_to_num_;
+    }
+
+    bool enable_inf_to_num() const
+    {
+        return enable_inf_to_num_;
+    }
+
+    bool enable_neginf_to_num() const
+    {
+        return enable_neginf_to_num_ || enable_inf_to_num_;
+    }
+
+    bool enable_nan_to_str() const
+    {
+        return enable_nan_to_str_;
+    }
+
+    bool enable_str_to_nan() const
+    {
+        return enable_str_to_nan_;
+    }
+
+    bool enable_inf_to_str() const
+    {
+        return enable_inf_to_str_;
+    }
+
+    bool enable_str_to_inf() const
+    {
+        return enable_str_to_inf_;
+    }
+
+    bool enable_neginf_to_str() const
+    {
+        return enable_neginf_to_str_ || enable_inf_to_str_;
+    }
+
+    bool enable_str_to_neginf() const
+    {
+        return enable_str_to_neginf_ || enable_str_to_inf_;
+    }
+
+    string_type nan_to_num() const
+    {
+        return nan_to_num_; 
+    }
+
+    string_type inf_to_num() const
+    {
+        return inf_to_num_; 
+    }
+
+    string_type neginf_to_num() const
+    {
+        if (enable_neginf_to_num_)
+        {
+            return neginf_to_num_;
+        }
+        else if (enable_inf_to_num_)
+        {
+            string_type s;
+            s.push_back('-');
+            s.append(inf_to_num_);
+            return s;
+        }
+        else
+        {
+            return neginf_to_num_; 
+        }
+    }
+
+    string_type nan_to_str() const
+    {
+        return nan_to_str_;
+    }
+
+    string_type inf_to_str() const
+    {
+        return inf_to_str_; 
+    }
+
+    string_type neginf_to_str() const
+    {
+        if (enable_neginf_to_str_)
+        {
+            return neginf_to_str_;
+        }
+        else if (enable_inf_to_str_)
+        {
+            string_type s;
+            s.push_back('-');
+            s.append(inf_to_str_);
+            return s;
+        }
+        else
+        {
+            return neginf_to_str_; // empty string
+        }
+    }
+};
+
+template <class CharT>
+class basic_csv_decode_options : public virtual basic_csv_options_common<CharT>
+{
+    friend class basic_csv_options<CharT>;
+    using super_type = basic_csv_options_common<CharT>;
+public:
+    using typename super_type::char_type;
+    using typename super_type::string_type;
+
+private:
+    bool assume_header_:1;
+    bool ignore_empty_values_:1;
+    bool ignore_empty_lines_:1;
+    bool trim_leading_:1;
+    bool trim_trailing_:1;
+    bool trim_leading_inside_quotes_:1;
+    bool trim_trailing_inside_quotes_:1;
+    bool unquoted_empty_value_is_null_:1;
+    bool infer_types_:1;
+    bool lossless_number_:1;
+    char_type comment_starter_;
+    csv_mapping_kind mapping_;
+    std::size_t header_lines_;
+    std::size_t max_lines_;
+    string_type column_types_;
+    string_type column_defaults_;
+public:
+    basic_csv_decode_options()
+        : assume_header_(false),
+          ignore_empty_values_(false),
+          ignore_empty_lines_(true),
+          trim_leading_(false),
+          trim_trailing_(false),
+          trim_leading_inside_quotes_(false),
+          trim_trailing_inside_quotes_(false),
+          unquoted_empty_value_is_null_(false),
+          infer_types_(true),
+          lossless_number_(false),
+          comment_starter_('\0'),
+          mapping_(),
+          header_lines_(0),
+          max_lines_((std::numeric_limits<std::size_t>::max)())
+    {}
+
+    basic_csv_decode_options(const basic_csv_decode_options& other) = default;
+
+    basic_csv_decode_options(basic_csv_decode_options&& other)
+        : super_type(std::forward<basic_csv_decode_options>(other)),
+          assume_header_(other.assume_header_),
+          ignore_empty_values_(other.ignore_empty_values_),
+          ignore_empty_lines_(other.ignore_empty_lines_),
+          trim_leading_(other.trim_leading_),
+          trim_trailing_(other.trim_trailing_),
+          trim_leading_inside_quotes_(other.trim_leading_inside_quotes_),
+          trim_trailing_inside_quotes_(other.trim_trailing_inside_quotes_),
+          unquoted_empty_value_is_null_(other.unquoted_empty_value_is_null_),
+          infer_types_(other.infer_types_),
+          lossless_number_(other.lossless_number_),
+          comment_starter_(other.comment_starter_),
+          mapping_(other.mapping_),
+          header_lines_(other.header_lines_),
+          max_lines_(other.max_lines_),
+          column_types_(std::move(other.column_types_)),
+          column_defaults_(std::move(other.column_defaults_))
+    {}
+
+    std::size_t header_lines() const 
+    {
+        return (assume_header_ && header_lines_ <= 1) ? 1 : header_lines_;
+    }
+
+    bool assume_header() const 
+    {
+        return assume_header_;
+    }
+
+    bool ignore_empty_values() const 
+    {
+        return ignore_empty_values_;
+    }
+
+    bool ignore_empty_lines() const 
+    {
+        return ignore_empty_lines_;
+    }
+
+    bool trim_leading() const 
+    {
+        return trim_leading_;
+    }
+
+    bool trim_trailing() const 
+    {
+        return trim_trailing_;
+    }
+
+    bool trim_leading_inside_quotes() const 
+    {
+        return trim_leading_inside_quotes_;
+    }
+
+    bool trim_trailing_inside_quotes() const 
+    {
+        return trim_trailing_inside_quotes_;
+    }
+
+    bool trim() const 
+    {
+        return trim_leading_ && trim_trailing_;
+    }
+
+    bool trim_inside_quotes() const 
+    {
+        return trim_leading_inside_quotes_ && trim_trailing_inside_quotes_;
+    }
+
+    bool unquoted_empty_value_is_null() const 
+    {
+        return unquoted_empty_value_is_null_;
+    }
+
+    bool infer_types() const 
+    {
+        return infer_types_;
+    }
+
+    bool lossless_number() const 
+    {
+        return lossless_number_;
+    }
+
+    char_type comment_starter() const 
+    {
+        return comment_starter_;
+    }
+
+    csv_mapping_kind mapping_kind() const 
+    {
+        return mapping_ != csv_mapping_kind() ? mapping_ : (assume_header() || this->column_names().size() > 0 ? csv_mapping_kind::n_objects : csv_mapping_kind::n_rows);
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+    csv_mapping_kind mapping() const 
+    {
+        return mapping_kind();
+    }
+#endif
+
+    std::size_t max_lines() const 
+    {
+        return max_lines_;
+    }
+
+    string_type column_types() const 
+    {
+        return column_types_;
+    }
+
+    string_type column_defaults() const 
+    {
+        return column_defaults_;
+    }
+};
+
+template <class CharT>
+class basic_csv_encode_options : public virtual basic_csv_options_common<CharT>
+{
+    friend class basic_csv_options<CharT>;
+    using super_type = basic_csv_options_common<CharT>;
+public:
+    using typename super_type::char_type;
+    using typename super_type::string_type;
+private:
+    quote_style_kind quote_style_;
+    float_chars_format float_format_;
+    int8_t precision_;
+    string_type line_delimiter_;
+public:
+    basic_csv_encode_options()
+      : quote_style_(quote_style_kind::minimal),
+        float_format_(float_chars_format::general),
+        precision_(0)
+    {
+        line_delimiter_.push_back('\n');
+    }
+
+    basic_csv_encode_options(const basic_csv_encode_options& other) = default;
+
+    basic_csv_encode_options(basic_csv_encode_options&& other)
+        : super_type(std::forward<basic_csv_encode_options>(other)),
+          quote_style_(other.quote_style_),
+          float_format_(other.float_format_),
+          precision_(other.precision_),
+          line_delimiter_(std::move(other.line_delimiter_))
+    {
+    }
+
+    quote_style_kind quote_style() const 
+    {
+        return quote_style_;
+    }
+
+    float_chars_format float_format() const 
+    {
+        return float_format_;
+    }
+
+    int8_t precision() const 
+    {
+        return precision_;
+    }
+
+    string_type line_delimiter() const
+    {
+        return line_delimiter_;
+    }
+};
+
+template <class CharT>
+class basic_csv_options final : public basic_csv_decode_options<CharT>, public basic_csv_encode_options<CharT>  
+{
+    using char_type = CharT;
+    using string_type = std::basic_string<CharT>;
+
+public:
+    using basic_csv_decode_options<CharT>::enable_str_to_nan;
+    using basic_csv_decode_options<CharT>::enable_str_to_inf;
+    using basic_csv_decode_options<CharT>::enable_str_to_neginf;
+    using basic_csv_decode_options<CharT>::nan_to_str;
+    using basic_csv_decode_options<CharT>::inf_to_str;
+    using basic_csv_decode_options<CharT>::neginf_to_str;
+    using basic_csv_decode_options<CharT>::nan_to_num;
+    using basic_csv_decode_options<CharT>::inf_to_num;
+    using basic_csv_decode_options<CharT>::neginf_to_num;
+    using basic_csv_decode_options<CharT>::field_delimiter;
+    using basic_csv_decode_options<CharT>::subfield_delimiter;
+    using basic_csv_decode_options<CharT>::quote_char;
+    using basic_csv_decode_options<CharT>::quote_escape_char;
+    using basic_csv_decode_options<CharT>::column_names;
+    using basic_csv_decode_options<CharT>::header_lines; 
+    using basic_csv_decode_options<CharT>::assume_header; 
+    using basic_csv_decode_options<CharT>::ignore_empty_values; 
+    using basic_csv_decode_options<CharT>::ignore_empty_lines; 
+    using basic_csv_decode_options<CharT>::trim_leading; 
+    using basic_csv_decode_options<CharT>::trim_trailing; 
+    using basic_csv_decode_options<CharT>::trim_leading_inside_quotes; 
+    using basic_csv_decode_options<CharT>::trim_trailing_inside_quotes; 
+    using basic_csv_decode_options<CharT>::trim; 
+    using basic_csv_decode_options<CharT>::trim_inside_quotes; 
+    using basic_csv_decode_options<CharT>::unquoted_empty_value_is_null; 
+    using basic_csv_decode_options<CharT>::infer_types; 
+    using basic_csv_decode_options<CharT>::lossless_number; 
+    using basic_csv_decode_options<CharT>::comment_starter; 
+    using basic_csv_decode_options<CharT>::mapping; 
+    using basic_csv_decode_options<CharT>::max_lines; 
+    using basic_csv_decode_options<CharT>::column_types; 
+    using basic_csv_decode_options<CharT>::column_defaults; 
+    using basic_csv_encode_options<CharT>::float_format;
+    using basic_csv_encode_options<CharT>::precision;
+    using basic_csv_encode_options<CharT>::line_delimiter;
+    using basic_csv_encode_options<CharT>::quote_style;
+
+    static constexpr size_t default_indent = 4;
+
+//  Constructors
+
+    basic_csv_options() = default;
+    basic_csv_options(const basic_csv_options&) = default;
+    basic_csv_options(basic_csv_options&&) = default;
+    basic_csv_options& operator=(const basic_csv_options&) = default;
+    basic_csv_options& operator=(basic_csv_options&&) = default;
+
+    basic_csv_options& float_format(float_chars_format value)
+    {
+        this->float_format_ = value;
+        return *this;
+    }
+
+    basic_csv_options& precision(int8_t value)
+    {
+        this->precision_ = value;
+        return *this;
+    }
+
+    basic_csv_options& header_lines(std::size_t value)
+    {
+        this->header_lines_ = value;
+        return *this;
+    }
+
+    basic_csv_options& assume_header(bool value)
+    {
+        this->assume_header_ = value;
+        return *this;
+    }
+
+    basic_csv_options& ignore_empty_values(bool value)
+    {
+        this->ignore_empty_values_ = value;
+        return *this;
+    }
+
+    basic_csv_options& ignore_empty_lines(bool value)
+    {
+        this->ignore_empty_lines_ = value;
+        return *this;
+    }
+
+    basic_csv_options& trim_leading(bool value)
+    {
+        this->trim_leading_ = value;
+        return *this;
+    }
+
+    basic_csv_options& trim_trailing(bool value)
+    {
+        this->trim_trailing_ = value;
+        return *this;
+    }
+
+    basic_csv_options& trim_leading_inside_quotes(bool value)
+    {
+        this->trim_leading_inside_quotes_ = value;
+        return *this;
+    }
+
+    basic_csv_options& trim_trailing_inside_quotes(bool value)
+    {
+        this->trim_trailing_inside_quotes_ = value;
+        return *this;
+    }
+
+    basic_csv_options& trim(bool value)
+    {
+        this->trim_leading_ = value;
+        this->trim_trailing_ = value;
+        return *this;
+    }
+
+    basic_csv_options& trim_inside_quotes(bool value)
+    {
+        this->trim_leading_inside_quotes_ = value;
+        this->trim_trailing_inside_quotes_ = value;
+        return *this;
+    }
+
+    basic_csv_options& unquoted_empty_value_is_null(bool value)
+    {
+        this->unquoted_empty_value_is_null_ = value;
+        return *this;
+    }
+
+    basic_csv_options& column_names(const string_type& value)
+    {
+        this->column_names_ = value;
+        return *this;
+    }
+
+    basic_csv_options& column_types(const string_type& value)
+    {
+        this->column_types_ = value;
+        return *this;
+    }
+
+    basic_csv_options& column_defaults(const string_type& value)
+    {
+        this->column_defaults_ = value;
+        return *this;
+    }
+
+    basic_csv_options& field_delimiter(char_type value)
+    {
+        this->field_delimiter_ = value;
+        return *this;
+    }
+
+    basic_csv_options& subfield_delimiter(char_type value)
+    {
+        this->subfield_delimiter_ = value;
+        return *this;
+    }
+
+    basic_csv_options& line_delimiter(const string_type& value)
+    {
+        this->line_delimiter_ = value;
+        return *this;
+    }
+
+    basic_csv_options& quote_char(char_type value)
+    {
+        this->quote_char_ = value;
+        return *this;
+    }
+
+    basic_csv_options& infer_types(bool value)
+    {
+        this->infer_types_ = value;
+        return *this;
+    }
+
+    basic_csv_options& lossless_number(bool value) 
+    {
+        this->lossless_number_ = value;
+        return *this;
+    }
+
+    basic_csv_options& quote_escape_char(char_type value)
+    {
+        this->quote_escape_char_ = value;
+        return *this;
+    }
+
+    basic_csv_options& comment_starter(char_type value)
+    {
+        this->comment_starter_ = value;
+        return *this;
+    }
+
+    basic_csv_options& quote_style(quote_style_kind value)
+    {
+        this->quote_style_ = value;
+        return *this;
+    }
+
+//#if !defined(JSONCONS_NO_DEPRECATED)
+    basic_csv_options& mapping(csv_mapping_kind value)
+    {
+        this->mapping_ = value;
+        return *this;
+    }
+//#endif
+
+    basic_csv_options& mapping_kind(csv_mapping_kind value)
+    {
+        this->mapping_ = value;
+        return *this;
+    }
+
+    basic_csv_options& max_lines(std::size_t value)
+    {
+        this->max_lines_ = value;
+        return *this;
+    }
+
+    basic_csv_options& nan_to_num(const string_type& value)
+    {
+        this->enable_nan_to_num_ = true;
+        this->nan_to_str_.clear();
+        this->nan_to_num_ = value;
+        return *this;
+    }
+
+    basic_csv_options& inf_to_num(const string_type& value)
+    {
+        this->enable_inf_to_num_ = true;
+        this->inf_to_str_.clear();
+        this->inf_to_num_ = value;
+        return *this;
+    }
+
+    basic_csv_options& neginf_to_num(const string_type& value)
+    {
+        this->enable_neginf_to_num_ = true;
+        this->neginf_to_str_.clear();
+        this->neginf_to_num_ = value;
+        return *this;
+    }
+
+    basic_csv_options& nan_to_str(const string_type& value, bool enable_inverse = true)
+    {
+        this->enable_nan_to_str_ = true;
+        this->enable_str_to_nan_ = enable_inverse;
+        this->nan_to_num_.clear();
+        this->nan_to_str_ = value;
+        return *this;
+    }
+
+    basic_csv_options& inf_to_str(const string_type& value, bool enable_inverse = true)
+    {
+        this->enable_inf_to_str_ = true;
+        this->enable_inf_to_str_ = enable_inverse;
+        this->inf_to_num_.clear();
+        this->inf_to_str_ = value;
+        return *this;
+    }
+
+    basic_csv_options& neginf_to_str(const string_type& value, bool enable_inverse = true)
+    {
+        this->enable_neginf_to_str_ = true;
+        this->enable_neginf_to_str_ = enable_inverse;
+        this->neginf_to_num_.clear();
+        this->neginf_to_str_ = value;
+        return *this;
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    JSONCONS_DEPRECATED_MSG("Instead, use float_format(float_chars_format)")
+    basic_csv_options& floating_point_format(float_chars_format value)
+    {
+        this->float_format_ = value;
+        return *this;
+    }
+#endif
+
+};
+
+using csv_options = basic_csv_options<char>;
+using wcsv_options = basic_csv_options<wchar_t>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+JSONCONS_DEPRECATED_MSG("Instead, use csv_options") typedef csv_options csv_parameters;
+JSONCONS_DEPRECATED_MSG("Instead, use wcsv_options") typedef wcsv_options wcsv_parameters;
+JSONCONS_DEPRECATED_MSG("Instead, use csv_options") typedef csv_options csv_serializing_options;
+JSONCONS_DEPRECATED_MSG("Instead, use wcsv_options") typedef wcsv_options wcsv_serializing_options;
+#endif
+
+
+}}
+#endif
diff --git a/include/jsoncons_ext/csv/csv_parser.hpp b/include/jsoncons_ext/csv/csv_parser.hpp
new file mode 100644
index 0000000..37887e2
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_parser.hpp
@@ -0,0 +1,2097 @@
+// Copyright 2015 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_PARSER_HPP
+#define JSONCONS_CSV_CSV_PARSER_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <sstream>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <cctype>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/json_reader.hpp>
+#include <jsoncons/json_filter.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons/detail/parse_number.hpp>
+#include <jsoncons_ext/csv/csv_error.hpp>
+#include <jsoncons_ext/csv/csv_options.hpp>
+
+namespace jsoncons { namespace csv {
+
+enum class csv_mode 
+{
+    initial,
+    header,
+    data,
+    subfields
+};
+
+enum class csv_parse_state 
+{
+    start,
+    cr, 
+    column_labels,
+    expect_comment_or_record,
+    expect_record,
+    end_record,
+    no_more_records,
+    comment,
+    between_values,
+    quoted_string,
+    unquoted_string,
+    before_unquoted_string,
+    escaped_value,
+    minus, 
+    zero,  
+    integer,
+    fraction,
+    exp1,
+    exp2,
+    exp3,
+    accept,
+    before_unquoted_field,
+    before_unquoted_field_tail, 
+    before_unquoted_field_tail1,
+    before_last_unquoted_field,
+    before_last_unquoted_field_tail,
+    before_unquoted_subfield,
+    before_unquoted_subfield_tail,
+    before_quoted_subfield,
+    before_quoted_subfield_tail,
+    before_quoted_field,
+    before_quoted_field_tail,
+    before_last_quoted_field,
+    before_last_quoted_field_tail,
+    done
+};
+
+enum class cached_state
+{
+    begin_object,
+    end_object,
+    begin_array,
+    end_array,
+    name,
+    item,
+    done
+};
+
+struct default_csv_parsing
+{
+    bool operator()(csv_errc, const ser_context&) noexcept
+    {
+        return false;
+    }
+};
+
+namespace detail {
+
+    template <class CharT,class TempAllocator>
+    class parse_event
+    {
+        using temp_allocator_type = TempAllocator;
+        using string_view_type = typename basic_json_visitor<CharT>::string_view_type;
+        using char_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<CharT>;
+        using byte_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<uint8_t>;                  
+        using string_type = std::basic_string<CharT,std::char_traits<CharT>,char_allocator_type>;
+        using byte_string_type = basic_byte_string<byte_allocator_type>;
+
+        staj_event_type event_type;
+        string_type string_value;
+        byte_string_type byte_string_value;
+        union
+        {
+            bool bool_value;
+            int64_t int64_value;
+            uint64_t uint64_value;
+            double double_value;
+        };
+        semantic_tag tag;
+    public:
+        parse_event(staj_event_type event_type, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(event_type), 
+              string_value(alloc),
+              byte_string_value(alloc),
+              tag(tag)
+        {
+        }
+
+        parse_event(const string_view_type& value, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(staj_event_type::string_value), 
+              string_value(value.data(),value.length(),alloc), 
+              byte_string_value(alloc),
+              tag(tag)
+        {
+        }
+
+        parse_event(const byte_string_view& value, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(staj_event_type::byte_string_value), 
+              string_value(alloc),
+              byte_string_value(value.data(),value.size(),alloc), 
+              tag(tag)
+        {
+        }
+
+        parse_event(bool value, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(staj_event_type::bool_value), 
+              string_value(alloc),
+              byte_string_value(alloc),
+              bool_value(value), 
+              tag(tag)
+        {
+        }
+
+        parse_event(int64_t value, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(staj_event_type::int64_value), 
+              string_value(alloc),
+              byte_string_value(alloc),
+              int64_value(value), 
+              tag(tag)
+        {
+        }
+
+        parse_event(uint64_t value, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(staj_event_type::uint64_value), 
+              string_value(alloc),
+              byte_string_value(alloc),
+              uint64_value(value), 
+              tag(tag)
+        {
+        }
+
+        parse_event(double value, semantic_tag tag, const TempAllocator& alloc)
+            : event_type(staj_event_type::double_value), 
+              string_value(alloc),
+              byte_string_value(alloc),
+              double_value(value), 
+              tag(tag)
+        {
+        }
+
+        parse_event(const parse_event&) = default;
+        parse_event(parse_event&&) = default;
+        parse_event& operator=(const parse_event&) = default;
+        parse_event& operator=(parse_event&&) = default;
+
+        bool replay(basic_json_visitor<CharT>& visitor) const
+        {
+            switch (event_type)
+            {
+                case staj_event_type::begin_array:
+                    return visitor.begin_array(tag, ser_context());
+                case staj_event_type::end_array:
+                    return visitor.end_array(ser_context());
+                case staj_event_type::string_value:
+                    return visitor.string_value(string_value, tag, ser_context());
+                case staj_event_type::byte_string_value:
+                case staj_event_type::null_value:
+                    return visitor.null_value(tag, ser_context());
+                case staj_event_type::bool_value:
+                    return visitor.bool_value(bool_value, tag, ser_context());
+                case staj_event_type::int64_value:
+                    return visitor.int64_value(int64_value, tag, ser_context());
+                case staj_event_type::uint64_value:
+                    return visitor.uint64_value(uint64_value, tag, ser_context());
+                case staj_event_type::double_value:
+                    return visitor.double_value(double_value, tag, ser_context());
+                default:
+                    return false;
+            }
+        }
+    };
+
+    template <class CharT, class TempAllocator>
+    class m_columns_filter : public basic_json_visitor<CharT>
+    {
+    public:
+        using string_view_type = typename basic_json_visitor<CharT>::string_view_type;
+        using char_type = CharT;
+        using temp_allocator_type = TempAllocator;
+
+        using char_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<CharT>;
+        using string_type = std::basic_string<CharT,std::char_traits<CharT>,char_allocator_type>;
+
+        using string_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<string_type>;
+        using parse_event_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<parse_event<CharT,TempAllocator>>;
+        using parse_event_vector_type = std::vector<parse_event<CharT,TempAllocator>, parse_event_allocator_type>;
+        using parse_event_vector_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<parse_event_vector_type>;
+    private:
+        TempAllocator alloc_;
+        std::size_t name_index_;
+        int level_;
+        cached_state state_;
+        std::size_t column_index_;
+        std::size_t row_index_;
+
+        std::vector<string_type, string_allocator_type> column_names_;
+        std::vector<parse_event_vector_type,parse_event_vector_allocator_type> cached_events_;
+    public:
+
+        m_columns_filter(const TempAllocator& alloc)
+            : alloc_(alloc),
+              name_index_(0), 
+              level_(0), 
+              state_(cached_state::begin_object), 
+              column_index_(0), 
+              row_index_(0),
+              column_names_(alloc),
+              cached_events_(alloc)
+        {
+        }
+
+        void reset()
+        {
+            name_index_ = 0;
+            level_ = 0;
+            state_ = cached_state::begin_object;
+            column_index_ = 0;
+            row_index_ = 0;
+            column_names_.clear();
+            cached_events_.clear();
+        }
+
+        bool done() const
+        {
+            return state_ == cached_state::done;
+        }
+
+        void initialize(const std::vector<string_type, string_allocator_type>& column_names)
+        {
+            for (const auto& name : column_names)
+            {
+                column_names_.push_back(name);
+                cached_events_.emplace_back(alloc_);
+            }
+            name_index_ = 0;
+            level_ = 0;
+            column_index_ = 0;
+            row_index_ = 0;
+            state_ = cached_state::begin_object;
+        }
+
+        void skip_column()
+        {
+            ++name_index_;
+        }
+
+        bool replay_parse_events(basic_json_visitor<CharT>& visitor)
+        {
+            bool more = true;
+            while (more)
+            {
+                switch (state_)
+                {
+                    case cached_state::begin_object:
+                        more = visitor.begin_object(semantic_tag::none, ser_context());
+                        column_index_ = 0;
+                        state_ = cached_state::name;
+                        break;
+                    case cached_state::end_object:
+                        more = visitor.end_object(ser_context());
+                        state_ = cached_state::done;
+                        break;
+                    case cached_state::name:
+                        if (column_index_ < column_names_.size())
+                        {
+                            more = visitor.key(column_names_[column_index_], ser_context());
+                            state_ = cached_state::begin_array;
+                        }
+                        else
+                        {
+                            state_ = cached_state::end_object;
+                        }
+                        break;
+                    case cached_state::begin_array:
+                        more = visitor.begin_array(semantic_tag::none, ser_context());
+                        row_index_ = 0;
+                        state_ = cached_state::item;
+                        break;
+                    case cached_state::end_array:
+                        more = visitor.end_array(ser_context());
+                        ++column_index_;
+                        state_ = cached_state::name;
+                        break;
+                    case cached_state::item:
+                        if (row_index_ < cached_events_[column_index_].size())
+                        {
+                            more = cached_events_[column_index_][row_index_].replay(visitor);
+                            ++row_index_;
+                        }
+                        else
+                        {
+                            state_ = cached_state::end_array;
+                        }
+                        break;
+                    default:
+                        more = false;
+                        break;
+                }
+            }
+            return more;
+        }
+
+        void visit_flush() override
+        {
+        }
+
+        bool visit_begin_object(semantic_tag, const ser_context&, std::error_code& ec) override
+        {
+            ec = csv_errc::invalid_parse_state;
+            return false;
+        }
+
+        bool visit_end_object(const ser_context&, std::error_code& ec) override
+        {
+            ec = csv_errc::invalid_parse_state;
+            return false;
+        }
+
+        bool visit_begin_array(semantic_tag tag, const ser_context&, std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(staj_event_type::begin_array, tag, alloc_);
+                
+                ++level_;
+            }
+            return true;
+        }
+
+        bool visit_end_array(const ser_context&, std::error_code&) override
+        {
+            if (level_ > 0)
+            {
+                cached_events_[name_index_].emplace_back(staj_event_type::end_array, semantic_tag::none, alloc_);
+                ++name_index_;
+                --level_;
+            }
+            else
+            {
+                name_index_ = 0;
+            }
+            return true;
+        }
+
+        bool visit_key(const string_view_type&, const ser_context&, std::error_code& ec) override
+        {
+            ec = csv_errc::invalid_parse_state;
+            return false;
+        }
+
+        bool visit_null(semantic_tag tag, const ser_context&, std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(staj_event_type::null_value, tag, alloc_);
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+
+        bool visit_string(const string_view_type& value, semantic_tag tag, const ser_context&, std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(value, tag, alloc_);
+
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+
+        bool visit_byte_string(const byte_string_view& value,
+                                  semantic_tag tag,
+                                  const ser_context&,
+                                  std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(value, tag, alloc_);
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+
+        bool visit_double(double value,
+                             semantic_tag tag, 
+                             const ser_context&,
+                             std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(value, tag, alloc_);
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+
+        bool visit_int64(int64_t value,
+                            semantic_tag tag,
+                            const ser_context&,
+                            std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(value, tag, alloc_);
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+
+        bool visit_uint64(uint64_t value,
+                             semantic_tag tag,
+                             const ser_context&,
+                             std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(value, tag, alloc_);
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+
+        bool visit_bool(bool value, semantic_tag tag, const ser_context&, std::error_code&) override
+        {
+            if (name_index_ < column_names_.size())
+            {
+                cached_events_[name_index_].emplace_back(value, tag, alloc_);
+                if (level_ == 0)
+                {
+                    ++name_index_;
+                }
+            }
+            return true;
+        }
+    };
+
+} // namespace detail
+
+template<class CharT,class TempAllocator=std::allocator<char>>
+class basic_csv_parser : public ser_context
+{
+public:
+    using string_view_type = jsoncons::basic_string_view<CharT>;
+    using char_type = CharT;
+private:
+    struct string_maps_to_double
+    {
+        string_view_type s;
+
+        bool operator()(const std::pair<string_view_type,double>& val) const
+        {
+            return val.first == s;
+        }
+    };
+
+    using temp_allocator_type = TempAllocator;
+    typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<CharT> char_allocator_type;
+    using string_type = std::basic_string<CharT,std::char_traits<CharT>,char_allocator_type>;
+    typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<string_type> string_allocator_type;
+    typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<csv_mode> csv_mode_allocator_type;
+    typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<csv_type_info> csv_type_info_allocator_type;
+    typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<std::vector<string_type,string_allocator_type>> string_vector_allocator_type;
+    typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<csv_parse_state> csv_parse_state_allocator_type;
+
+    static constexpr int default_depth = 3;
+
+    temp_allocator_type alloc_;
+    csv_parse_state state_;
+    basic_json_visitor<CharT>* visitor_;
+    std::function<bool(csv_errc,const ser_context&)> err_handler_;
+    std::size_t column_;
+    std::size_t line_;
+    int depth_;
+    const basic_csv_decode_options<CharT> options_;
+    std::size_t column_index_;
+    std::size_t level_;
+    std::size_t offset_;
+    jsoncons::detail::chars_to to_double_; 
+    const CharT* begin_input_;
+    const CharT* input_end_;
+    const CharT* input_ptr_;
+    bool more_;
+    std::size_t header_line_;
+
+    detail::m_columns_filter<CharT,TempAllocator> m_columns_filter_;
+    std::vector<csv_mode,csv_mode_allocator_type> stack_;
+    std::vector<string_type,string_allocator_type> column_names_;
+    std::vector<csv_type_info,csv_type_info_allocator_type> column_types_;
+    std::vector<string_type,string_allocator_type> column_defaults_;
+    std::vector<csv_parse_state,csv_parse_state_allocator_type> state_stack_;
+    string_type buffer_;
+    std::vector<std::pair<string_view_type,double>> string_double_map_;
+
+public:
+    basic_csv_parser(const TempAllocator& alloc = TempAllocator())
+       : basic_csv_parser(basic_csv_decode_options<CharT>(), 
+                          default_csv_parsing(),
+                          alloc)
+    {
+    }
+
+    basic_csv_parser(const basic_csv_decode_options<CharT>& options,
+                     const TempAllocator& alloc = TempAllocator())
+        : basic_csv_parser(options, 
+                           default_csv_parsing(),
+                           alloc)
+    {
+    }
+
+    basic_csv_parser(std::function<bool(csv_errc,const ser_context&)> err_handler,
+                     const TempAllocator& alloc = TempAllocator())
+        : basic_csv_parser(basic_csv_decode_options<CharT>(), 
+                           err_handler,
+                           alloc)
+    {
+    }
+
+    basic_csv_parser(const basic_csv_decode_options<CharT>& options,
+                     std::function<bool(csv_errc,const ser_context&)> err_handler,
+                     const TempAllocator& alloc = TempAllocator())
+       : alloc_(alloc),
+         state_(csv_parse_state::start),
+         visitor_(nullptr),
+         err_handler_(err_handler),
+         column_(1),
+         line_(1),
+         depth_(default_depth),
+         options_(options),
+         column_index_(0),
+         level_(0),
+         offset_(0),
+         begin_input_(nullptr),
+         input_end_(nullptr),
+         input_ptr_(nullptr),
+         more_(true),
+         header_line_(1),
+         m_columns_filter_(alloc),
+         stack_(alloc),
+         column_names_(alloc),
+         column_types_(alloc),
+         column_defaults_(alloc),
+         state_stack_(alloc),
+         buffer_(alloc)
+    {
+        if (options_.enable_str_to_nan())
+        {
+            string_double_map_.emplace_back(options_.nan_to_str(),std::nan(""));
+        }
+        if (options_.enable_str_to_inf())
+        {
+            string_double_map_.emplace_back(options_.inf_to_str(),std::numeric_limits<double>::infinity());
+        }
+        if (options_.enable_str_to_neginf())
+        {
+            string_double_map_.emplace_back(options_.neginf_to_str(),-std::numeric_limits<double>::infinity());
+        }
+
+        initialize();
+    }
+
+    ~basic_csv_parser() noexcept
+    {
+    }
+
+    bool done() const
+    {
+        return state_ == csv_parse_state::done;
+    }
+
+    bool accept() const
+    {
+        return state_ == csv_parse_state::accept || state_ == csv_parse_state::done;
+    }
+
+    bool stopped() const
+    {
+        return !more_;
+    }
+
+    bool source_exhausted() const
+    {
+        return input_ptr_ == input_end_;
+    }
+
+    const std::vector<string_type,string_allocator_type>& column_labels() const
+    {
+        return column_names_;
+    }
+
+    void reinitialize()
+    {
+        state_ = csv_parse_state::start;
+        visitor_ = nullptr;
+        column_ = 1;
+        line_ = 1;
+        depth_ = default_depth;
+        column_index_ = 0;
+        level_ = 0;
+        offset_ = 0;
+        begin_input_ = nullptr;
+        input_end_ = nullptr;
+        input_ptr_ = nullptr;
+        more_ = true;
+        header_line_ = 1;
+        m_columns_filter_.reset();
+        stack_.clear();
+        column_names_.clear();
+        column_types_.clear();
+        column_defaults_.clear();
+        state_stack_.clear();
+        buffer_.clear();
+
+        initialize();
+    }
+
+    void restart()
+    {
+        more_ = true;
+    }
+
+    void parse_some(basic_json_visitor<CharT>& visitor)
+    {
+        std::error_code ec;
+        parse_some(visitor,ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,line_,column_));
+        }
+    }
+
+    void parse_some(basic_json_visitor<CharT>& visitor, std::error_code& ec)
+    {
+        switch (options_.mapping_kind())
+        {
+            case csv_mapping_kind::m_columns:
+                visitor_ = &m_columns_filter_;
+                break;
+            default:
+                visitor_ = std::addressof(visitor);
+                break;
+        } 
+
+        const CharT* local_input_end = input_end_;
+
+        if (input_ptr_ == local_input_end && more_)
+        {
+            switch (state_)
+            {
+                case csv_parse_state::start:
+                    ec = csv_errc::source_error;
+                    more_ = false;
+                    return;
+                case csv_parse_state::before_unquoted_field:
+                case csv_parse_state::before_last_unquoted_field:
+                    end_unquoted_string_value(ec);
+                    state_ = csv_parse_state::before_last_unquoted_field_tail;
+                    break;
+                case csv_parse_state::before_last_unquoted_field_tail:
+                    if (stack_.back() == csv_mode::subfields)
+                    {
+                        stack_.pop_back();
+                        more_ = visitor_->end_array(*this, ec);
+                    }
+                    ++column_index_;
+                    state_ = csv_parse_state::end_record;
+                    break;
+                case csv_parse_state::before_unquoted_string: 
+                    buffer_.clear();
+                    JSONCONS_FALLTHROUGH;
+                case csv_parse_state::unquoted_string: 
+                    if (options_.trim_leading() || options_.trim_trailing())
+                    {
+                        trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                    }
+                    if (options_.ignore_empty_values() && buffer_.empty())
+                    {
+                        state_ = csv_parse_state::end_record;
+                    }
+                    else
+                    {
+                        before_value(ec);
+                        state_ = csv_parse_state::before_unquoted_field;
+                    }
+                    break;
+                case csv_parse_state::before_last_quoted_field:
+                    end_quoted_string_value(ec);
+                    ++column_index_;
+                    state_ = csv_parse_state::end_record;
+                    break;
+                case csv_parse_state::escaped_value:
+                    if (options_.quote_escape_char() == options_.quote_char())
+                    {
+                        if (!(options_.ignore_empty_values() && buffer_.empty()))
+                        {
+                            before_value(ec);
+                            ++column_;
+                            state_ = csv_parse_state::before_last_quoted_field;
+                        }
+                        else
+                        {
+                            state_ = csv_parse_state::end_record;
+                        }
+                    }
+                    else
+                    {
+                        ec = csv_errc::invalid_escaped_char;
+                        more_ = false;
+                        return;
+                    }
+                    break;
+                case csv_parse_state::end_record:
+                    if (column_index_ > 0)
+                    {
+                        after_record(ec);
+                    }
+                    state_ = csv_parse_state::no_more_records;
+                    break;
+                case csv_parse_state::no_more_records: 
+                    switch (stack_.back()) 
+                    {
+                        case csv_mode::header:
+                            stack_.pop_back();
+                            break;
+                        case csv_mode::data:
+                            stack_.pop_back();
+                            break;
+                        default:
+                            break;
+                    }
+                    more_ = visitor_->end_array(*this, ec);
+                    if (options_.mapping_kind() == csv_mapping_kind::m_columns)
+                    {
+                        if (!m_columns_filter_.done())
+                        {
+                            more_ = m_columns_filter_.replay_parse_events(visitor);
+                        }
+                        else
+                        {
+                            state_ = csv_parse_state::accept;
+                        }
+                    }
+                    else
+                    {
+                        state_ = csv_parse_state::accept;
+                    }
+                    break;
+                case csv_parse_state::accept:
+                    if (!(stack_.size() == 1 && stack_.back() == csv_mode::initial))
+                    {
+                        err_handler_(csv_errc::unexpected_eof, *this);
+                        ec = csv_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    stack_.pop_back();
+                    visitor_->flush();
+                    state_ = csv_parse_state::done;
+                    more_ = false;
+                    return;
+                default:
+                    state_ = csv_parse_state::end_record;
+                    break;
+            }
+        }
+
+        for (; (input_ptr_ < local_input_end) && more_;)
+        {
+            CharT curr_char = *input_ptr_;
+
+            switch (state_) 
+            {
+                case csv_parse_state::cr:
+                    ++line_;
+                    column_ = 1;
+                    switch (*input_ptr_)
+                    {
+                        case '\n':
+                            ++input_ptr_;
+                            state_ = pop_state();
+                            break;
+                        default:
+                            state_ = pop_state();
+                            break;
+                    }
+                    break;
+                case csv_parse_state::start:
+                    if (options_.mapping_kind() != csv_mapping_kind::m_columns)
+                    {
+                        more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                    }
+                    if (options_.assume_header() && options_.mapping_kind() == csv_mapping_kind::n_rows && options_.column_names().size() > 0)
+                    {
+                        column_index_ = 0;
+                        state_ = csv_parse_state::column_labels;
+                        more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                        state_ = csv_parse_state::expect_comment_or_record;
+                    }
+                    else
+                    {
+                        state_ = csv_parse_state::expect_comment_or_record;
+                    }
+                    break;
+                case csv_parse_state::column_labels:
+                    if (column_index_ < column_names_.size())
+                    {
+                        more_ = visitor_->string_value(column_names_[column_index_], semantic_tag::none, *this, ec);
+                        ++column_index_;
+                    }
+                    else
+                    {
+                        more_ = visitor_->end_array(*this, ec);
+                        state_ = csv_parse_state::expect_comment_or_record; 
+                        //stack_.back() = csv_mode::data;
+                        column_index_ = 0;
+                    }
+                    break;
+                case csv_parse_state::comment: 
+                    switch (curr_char)
+                    {
+                        case '\n':
+                        {
+                            ++line_;
+                            if (stack_.back() == csv_mode::header)
+                            {
+                                ++header_line_;
+                            }
+                            column_ = 1;
+                            state_ = csv_parse_state::expect_comment_or_record;
+                            break;
+                        }
+                        case '\r':
+                            ++line_;
+                            if (stack_.back() == csv_mode::header)
+                            {
+                                ++header_line_;
+                            }
+                            column_ = 1;
+                            state_ = csv_parse_state::expect_comment_or_record;
+                            push_state(state_);
+                            state_ = csv_parse_state::cr;
+                            break;
+                        default:
+                            ++column_;
+                            break;
+                    }
+                    ++input_ptr_;
+                    break;
+                
+                case csv_parse_state::expect_comment_or_record:
+                    buffer_.clear();
+                    if (curr_char == options_.comment_starter())
+                    {
+                        state_ = csv_parse_state::comment;
+                        ++column_;
+                        ++input_ptr_;
+                    }
+                    else
+                    {
+                        state_ = csv_parse_state::expect_record;
+                    }
+                    break;
+                case csv_parse_state::quoted_string: 
+                    {
+                        if (curr_char == options_.quote_escape_char())
+                        {
+                            state_ = csv_parse_state::escaped_value;
+                        }
+                        else if (curr_char == options_.quote_char())
+                        {
+                            state_ = csv_parse_state::between_values;
+                        }
+                        else
+                        {
+                            buffer_.push_back(static_cast<CharT>(curr_char));
+                        }
+                    }
+                    ++column_;
+                    ++input_ptr_;
+                    break;
+                case csv_parse_state::escaped_value: 
+                    {
+                        if (curr_char == options_.quote_char())
+                        {
+                            buffer_.push_back(static_cast<CharT>(curr_char));
+                            state_ = csv_parse_state::quoted_string;
+                            ++column_;
+                            ++input_ptr_;
+                        }
+                        else if (options_.quote_escape_char() == options_.quote_char())
+                        {
+                            state_ = csv_parse_state::between_values;
+                        }
+                        else
+                        {
+                            ec = csv_errc::invalid_escaped_char;
+                            more_ = false;
+                            return;
+                        }
+                    }
+                    break;
+                case csv_parse_state::between_values:
+                    switch (curr_char)
+                    {
+                        case '\r':
+                        case '\n':
+                        {
+                            if (options_.trim_leading() || options_.trim_trailing())
+                            {
+                                trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                            }
+                            if (!(options_.ignore_empty_values() && buffer_.empty()))
+                            {
+                                before_value(ec);
+                                state_ = csv_parse_state::before_last_quoted_field;
+                            }
+                            else
+                            {
+                                state_ = csv_parse_state::end_record;
+                            }
+                            break;
+                        }
+                        default:
+                            if (curr_char == options_.field_delimiter())
+                            {
+                                if (options_.trim_leading() || options_.trim_trailing())
+                                {
+                                    trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                                }
+                                before_value(ec);
+                                state_ = csv_parse_state::before_quoted_field;
+                            }
+                            else if (options_.subfield_delimiter() != char_type() && curr_char == options_.subfield_delimiter())
+                            {
+                                if (options_.trim_leading() || options_.trim_trailing())
+                                {
+                                    trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                                }
+                                before_value(ec);
+                                state_ = csv_parse_state::before_quoted_subfield;
+                            }
+                            else if (curr_char == ' ' || curr_char == '\t')
+                            {
+                                ++column_;
+                                ++input_ptr_;
+                            }
+                            else
+                            {
+                                ec = csv_errc::unexpected_char_between_fields;
+                                more_ = false;
+                                return;
+                            }
+                            break;
+                    }
+                    break;
+                case csv_parse_state::before_unquoted_string: 
+                {
+                    buffer_.clear();
+                    state_ = csv_parse_state::unquoted_string;
+                    break;
+                }
+                case csv_parse_state::before_unquoted_field:
+                    end_unquoted_string_value(ec);
+                    state_ = csv_parse_state::before_unquoted_field_tail;
+                    break;
+                case csv_parse_state::before_unquoted_field_tail:
+                {
+                    if (stack_.back() == csv_mode::subfields)
+                    {
+                        stack_.pop_back();
+                        more_ = visitor_->end_array(*this, ec);
+                    }
+                    ++column_index_;
+                    state_ = csv_parse_state::before_unquoted_string;
+                    ++column_;
+                    ++input_ptr_;
+                    break;
+                }
+                case csv_parse_state::before_unquoted_field_tail1:
+                {
+                    if (stack_.back() == csv_mode::subfields)
+                    {
+                        stack_.pop_back();
+                        more_ = visitor_->end_array(*this, ec);
+                    }
+                    state_ = csv_parse_state::end_record;
+                    ++column_;
+                    ++input_ptr_;
+                    break;
+                }
+
+                case csv_parse_state::before_last_unquoted_field:
+                    end_unquoted_string_value(ec);
+                    state_ = csv_parse_state::before_last_unquoted_field_tail;
+                    break;
+
+                case csv_parse_state::before_last_unquoted_field_tail:
+                    if (stack_.back() == csv_mode::subfields)
+                    {
+                        stack_.pop_back();
+                        more_ = visitor_->end_array(*this, ec);
+                    }
+                    ++column_index_;
+                    state_ = csv_parse_state::end_record;
+                    break;
+
+                case csv_parse_state::before_unquoted_subfield:
+                    if (stack_.back() == csv_mode::data)
+                    {
+                        stack_.push_back(csv_mode::subfields);
+                        more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                    }
+                    state_ = csv_parse_state::before_unquoted_subfield_tail;
+                    break; 
+                case csv_parse_state::before_unquoted_subfield_tail:
+                    end_unquoted_string_value(ec);
+                    state_ = csv_parse_state::before_unquoted_string;
+                    ++column_;
+                    ++input_ptr_;
+                    break;
+                case csv_parse_state::before_quoted_field:
+                    end_quoted_string_value(ec);
+                    state_ = csv_parse_state::before_unquoted_field_tail; // return to unquoted
+                    break;
+                case csv_parse_state::before_quoted_subfield:
+                    if (stack_.back() == csv_mode::data)
+                    {
+                        stack_.push_back(csv_mode::subfields);
+                        more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                    }
+                    state_ = csv_parse_state::before_quoted_subfield_tail;
+                    break; 
+                case csv_parse_state::before_quoted_subfield_tail:
+                    end_quoted_string_value(ec);
+                    state_ = csv_parse_state::before_unquoted_string;
+                    ++column_;
+                    ++input_ptr_;
+                    break;
+                case csv_parse_state::before_last_quoted_field:
+                    end_quoted_string_value(ec);
+                    state_ = csv_parse_state::before_last_quoted_field_tail;
+                    break;
+                case csv_parse_state::before_last_quoted_field_tail:
+                    if (stack_.back() == csv_mode::subfields)
+                    {
+                        stack_.pop_back();
+                        more_ = visitor_->end_array(*this, ec);
+                    }
+                    ++column_index_;
+                    state_ = csv_parse_state::end_record;
+                    break;
+                case csv_parse_state::unquoted_string: 
+                {
+                    switch (curr_char)
+                    {
+                        case '\n':
+                        case '\r':
+                        {
+                            if (options_.trim_leading() || options_.trim_trailing())
+                            {
+                                trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                            }
+                            if (!(options_.ignore_empty_values() && buffer_.empty()))
+                            {
+                                before_value(ec);
+                                state_ = csv_parse_state::before_last_unquoted_field;
+                            }
+                            else
+                            {
+                                state_ = csv_parse_state::end_record;
+                            }
+                            break;
+                        }
+                        default:
+                            if (curr_char == options_.field_delimiter())
+                            {
+                                if (options_.trim_leading() || options_.trim_trailing())
+                                {
+                                    trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                                }
+                                before_value(ec);
+                                state_ = csv_parse_state::before_unquoted_field;
+                            }
+                            else if (options_.subfield_delimiter() != char_type() && curr_char == options_.subfield_delimiter())
+                            {
+                                if (options_.trim_leading() || options_.trim_trailing())
+                                {
+                                    trim_string_buffer(options_.trim_leading(),options_.trim_trailing());
+                                }
+                                before_value(ec);
+                                state_ = csv_parse_state::before_unquoted_subfield;
+                            }
+                            else if (curr_char == options_.quote_char())
+                            {
+                                buffer_.clear();
+                                state_ = csv_parse_state::quoted_string;
+                                ++column_;
+                                ++input_ptr_;
+                            }
+                            else
+                            {
+                                buffer_.push_back(static_cast<CharT>(curr_char));
+                                ++column_;
+                                ++input_ptr_;
+                            }
+                            break;
+                    }
+                    break;
+                }
+                case csv_parse_state::expect_record: 
+                {
+                    switch (curr_char)
+                    {
+                        case '\n':
+                        {
+                            if (!options_.ignore_empty_lines())
+                            {
+                                before_record(ec);
+                                state_ = csv_parse_state::end_record;
+                            }
+                            else
+                            {
+                                ++line_;
+                                column_ = 1;
+                                state_ = csv_parse_state::expect_comment_or_record;
+                                ++input_ptr_;
+                            }
+                            break;
+                        }
+                        case '\r':
+                            if (!options_.ignore_empty_lines())
+                            {
+                                before_record(ec);
+                                state_ = csv_parse_state::end_record;
+                            }
+                            else
+                            {
+                                ++line_;
+                                column_ = 1;
+                                state_ = csv_parse_state::expect_comment_or_record;
+                                ++input_ptr_;
+                                push_state(state_);
+                                state_ = csv_parse_state::cr;
+                            }
+                            break;
+                        case ' ':
+                        case '\t':
+                            if (!options_.trim_leading())
+                            {
+                                buffer_.push_back(static_cast<CharT>(curr_char));
+                                before_record(ec);
+                                state_ = csv_parse_state::unquoted_string;
+                            }
+                            ++column_;
+                            ++input_ptr_;
+                            break;
+                        default:
+                            before_record(ec);
+                            if (curr_char == options_.quote_char())
+                            {
+                                buffer_.clear();
+                                state_ = csv_parse_state::quoted_string;
+                                ++column_;
+                                ++input_ptr_;
+                            }
+                            else
+                            {
+                                state_ = csv_parse_state::unquoted_string;
+                            }
+                            break;
+                        }
+                    break;
+                    }
+                case csv_parse_state::end_record: 
+                {
+                    switch (curr_char)
+                    {
+                        case '\n':
+                        {
+                            ++line_;
+                            column_ = 1;
+                            state_ = csv_parse_state::expect_comment_or_record;
+                            after_record(ec);
+                            ++input_ptr_;
+                            break;
+                        }
+                        case '\r':
+                            ++line_;
+                            column_ = 1;
+                            state_ = csv_parse_state::expect_comment_or_record;
+                            after_record(ec);
+                            push_state(state_);
+                            state_ = csv_parse_state::cr;
+                            ++input_ptr_;
+                            break;
+                        case ' ':
+                        case '\t':
+                            ++column_;
+                            ++input_ptr_;
+                            break;
+                        default:
+                            err_handler_(csv_errc::syntax_error, *this);
+                            ec = csv_errc::syntax_error;
+                            more_ = false;
+                            return;
+                        }
+                    break;
+                }
+                default:
+                    err_handler_(csv_errc::invalid_parse_state, *this);
+                    ec = csv_errc::invalid_parse_state;
+                    more_ = false;
+                    return;
+            }
+            if (line_ > options_.max_lines())
+            {
+                state_ = csv_parse_state::done;
+                more_ = false;
+            }
+        }
+    }
+
+    void finish_parse()
+    {
+        std::error_code ec;
+        finish_parse(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,line_,column_));
+        }
+    }
+
+    void finish_parse(std::error_code& ec)
+    {
+        while (more_)
+        {
+            parse_some(ec);
+        }
+    }
+
+    csv_parse_state state() const
+    {
+        return state_;
+    }
+
+    void update(const string_view_type sv)
+    {
+        update(sv.data(),sv.length());
+    }
+
+    void update(const CharT* data, std::size_t length)
+    {
+        begin_input_ = data;
+        input_end_ = data + length;
+        input_ptr_ = begin_input_;
+    }
+
+    std::size_t line() const override
+    {
+        return line_;
+    }
+
+    std::size_t column() const override
+    {
+        return column_;
+    }
+
+private:
+    void initialize()
+    {
+        jsoncons::csv::detail::parse_column_names(options_.column_names(), column_names_);
+        jsoncons::csv::detail::parse_column_types(options_.column_types(), column_types_);
+        jsoncons::csv::detail::parse_column_names(options_.column_defaults(), column_defaults_);
+
+        stack_.reserve(default_depth);
+        stack_.push_back(csv_mode::initial);
+        stack_.push_back((options_.header_lines() > 0) ? csv_mode::header
+                                                       : csv_mode::data);
+    }
+
+    // name
+    void before_value(std::error_code& ec)
+    {
+        switch (stack_.back())
+        {
+            case csv_mode::header:
+                if (options_.trim_leading_inside_quotes() || options_.trim_trailing_inside_quotes())
+                {
+                    trim_string_buffer(options_.trim_leading_inside_quotes(),options_.trim_trailing_inside_quotes());
+                }
+                if (line_ == header_line_)
+                {
+                    column_names_.push_back(buffer_);
+                    if (options_.assume_header() && options_.mapping_kind() == csv_mapping_kind::n_rows)
+                    {
+                        more_ = visitor_->string_value(buffer_, semantic_tag::none, *this, ec);
+                    }
+                }
+                break;
+            case csv_mode::data:
+                if (options_.mapping_kind() == csv_mapping_kind::n_objects)
+                {
+                    if (!(options_.ignore_empty_values() && buffer_.empty()))
+                    {
+                        if (column_index_ < column_names_.size() + offset_)
+                        {
+                            more_ = visitor_->key(column_names_[column_index_ - offset_], *this, ec);
+                        }
+                    }
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    // begin_array or begin_record
+    void before_record(std::error_code& ec)
+    {
+        offset_ = 0;
+
+        switch (stack_.back())
+        {
+            case csv_mode::header:
+                if (options_.assume_header() && line_ == header_line_)
+                {
+                    if (options_.mapping_kind() == csv_mapping_kind::n_rows)
+                    {
+                        more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                    }
+                }
+                break;
+            case csv_mode::data:
+                switch (options_.mapping_kind())
+                {
+                    case csv_mapping_kind::n_rows:
+                        more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                        break;
+                    case csv_mapping_kind::n_objects:
+                        more_ = visitor_->begin_object(semantic_tag::none, *this, ec);
+                        break;
+                    case csv_mapping_kind::m_columns:
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    // end_array, begin_array, string_value (headers)
+    void after_record(std::error_code& ec)
+    {
+        if (column_types_.size() > 0)
+        {
+            if (level_ > 0)
+            {
+                more_ = visitor_->end_array(*this, ec);
+                level_ = 0;
+            }
+        }
+        switch (stack_.back())
+        {
+            case csv_mode::header:
+                if (line_ >= options_.header_lines())
+                {
+                    stack_.back() = csv_mode::data;
+                }
+                switch (options_.mapping_kind())
+                {
+                    case csv_mapping_kind::n_rows:
+                        if (options_.assume_header())
+                        {
+                            more_ = visitor_->end_array(*this, ec);
+                        }
+                        break;
+                    case csv_mapping_kind::m_columns:
+                        m_columns_filter_.initialize(column_names_);
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            case csv_mode::data:
+            case csv_mode::subfields:
+            {
+                switch (options_.mapping_kind())
+                {
+                    case csv_mapping_kind::n_rows:
+                        more_ = visitor_->end_array(*this, ec);
+                        break;
+                    case csv_mapping_kind::n_objects:
+                        more_ = visitor_->end_object(*this, ec);
+                        break;
+                    case csv_mapping_kind::m_columns:
+                        more_ = visitor_->end_array(*this, ec);
+                        break;
+                }
+                break;
+            }
+            default:
+                break;
+        }
+        column_index_ = 0;
+    }
+
+    void trim_string_buffer(bool trim_leading, bool trim_trailing)
+    {
+        std::size_t start = 0;
+        std::size_t length = buffer_.length();
+        if (trim_leading)
+        {
+            bool done = false;
+            while (!done && start < buffer_.length())
+            {
+                if ((buffer_[start] < 256) && std::isspace(buffer_[start]))
+                {
+                    ++start;
+                }
+                else
+                {
+                    done = true;
+                }
+            }
+        }
+        if (trim_trailing)
+        {
+            bool done = false;
+            while (!done && length > 0)
+            {
+                if ((buffer_[length-1] < 256) && std::isspace(buffer_[length-1]))
+                {
+                    --length;
+                }
+                else
+                {
+                    done = true;
+                }
+            }
+        }
+        if (start != 0 || length != buffer_.size())
+        {
+            buffer_ = buffer_.substr(start,length-start);
+        }
+    }
+
+    /*
+        end_array, begin_array, xxx_value (end_value)
+    */
+    void end_unquoted_string_value(std::error_code& ec) 
+    {
+        switch (stack_.back())
+        {
+            case csv_mode::data:
+            case csv_mode::subfields:
+                switch (options_.mapping_kind())
+                {
+                case csv_mapping_kind::n_rows:
+                    if (options_.unquoted_empty_value_is_null() && buffer_.length() == 0)
+                    {
+                        more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                    }
+                    else
+                    {
+                        end_value(options_.infer_types(), ec);
+                    }
+                    break;
+                case csv_mapping_kind::n_objects:
+                    if (!(options_.ignore_empty_values() && buffer_.empty()))
+                    {
+                        if (column_index_ < column_names_.size() + offset_)
+                        {
+                            if (options_.unquoted_empty_value_is_null() && buffer_.length() == 0)
+                            {
+                                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                            }
+                            else
+                            {
+                                end_value(options_.infer_types(), ec);
+                            }
+                        }
+                        else if (level_ > 0)
+                        {
+                            if (options_.unquoted_empty_value_is_null() && buffer_.length() == 0)
+                            {
+                                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                            }
+                            else
+                            {
+                                end_value(options_.infer_types(), ec);
+                            }
+                        }
+                    }
+                    break;
+                case csv_mapping_kind::m_columns:
+                    if (!(options_.ignore_empty_values() && buffer_.empty()))
+                    {
+                        end_value(options_.infer_types(), ec);
+                    }
+                    else
+                    {
+                        m_columns_filter_.skip_column();
+                    }
+                    break;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    void end_quoted_string_value(std::error_code& ec) 
+    {
+        switch (stack_.back())
+        {
+            case csv_mode::data:
+            case csv_mode::subfields:
+                if (options_.trim_leading_inside_quotes() || options_.trim_trailing_inside_quotes())
+                {
+                    trim_string_buffer(options_.trim_leading_inside_quotes(),options_.trim_trailing_inside_quotes());
+                }
+                switch (options_.mapping_kind())
+                {
+                case csv_mapping_kind::n_rows:
+                    end_value(false, ec);
+                    break;
+                case csv_mapping_kind::n_objects:
+                    if (!(options_.ignore_empty_values() && buffer_.empty()))
+                    {
+                        if (column_index_ < column_names_.size() + offset_)
+                        {
+                            if (options_.unquoted_empty_value_is_null() && buffer_.length() == 0)
+                            {
+                                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                            }
+                            else 
+                            {
+                                end_value(false, ec);
+                            }
+                        }
+                        else if (level_ > 0)
+                        {
+                            if (options_.unquoted_empty_value_is_null() && buffer_.length() == 0)
+                            {
+                                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                            }
+                            else
+                            {
+                                end_value(false, ec);
+                            }
+                        }
+                    }
+                    break;
+                case csv_mapping_kind::m_columns:
+                    if (!(options_.ignore_empty_values() && buffer_.empty()))
+                    {
+                        end_value(false, ec);
+                    }
+                    else
+                    {
+                        m_columns_filter_.skip_column();
+                    }
+                    break;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    void end_value(bool infer_types, std::error_code&  ec)
+    {
+        auto it = std::find_if(string_double_map_.begin(), string_double_map_.end(), string_maps_to_double{ buffer_ });
+        if (it != string_double_map_.end())
+        {
+            more_ = visitor_->double_value(it->second, semantic_tag::none, *this, ec);
+        }
+        else if (column_index_ < column_types_.size() + offset_)
+        {
+            if (column_types_[column_index_ - offset_].col_type == csv_column_type::repeat_t)
+            {
+                offset_ = offset_ + column_types_[column_index_ - offset_].rep_count;
+                if (column_index_ - offset_ + 1 < column_types_.size())
+                {
+                    if (column_index_ == offset_ || level_ > column_types_[column_index_-offset_].level)
+                    {
+                        more_ = visitor_->end_array(*this, ec);
+                    }
+                    level_ = column_index_ == offset_ ? 0 : column_types_[column_index_ - offset_].level;
+                }
+            }
+            if (level_ < column_types_[column_index_ - offset_].level)
+            {
+                more_ = visitor_->begin_array(semantic_tag::none, *this, ec);
+                level_ = column_types_[column_index_ - offset_].level;
+            }
+            else if (level_ > column_types_[column_index_ - offset_].level)
+            {
+                more_ = visitor_->end_array(*this, ec);
+                level_ = column_types_[column_index_ - offset_].level;
+            }
+            switch (column_types_[column_index_ - offset_].col_type)
+            {
+                case csv_column_type::integer_t:
+                    {
+                        std::basic_istringstream<CharT,std::char_traits<CharT>,char_allocator_type> iss{buffer_};
+                        int64_t val;
+                        iss >> val;
+                        if (!iss.fail())
+                        {
+                            more_ = visitor_->int64_value(val, semantic_tag::none, *this, ec);
+                        }
+                        else
+                        {
+                            if (column_index_ - offset_ < column_defaults_.size() && column_defaults_[column_index_ - offset_].length() > 0)
+                            {
+                                basic_json_parser<CharT,temp_allocator_type> parser(alloc_);
+                                parser.update(column_defaults_[column_index_ - offset_].data(),column_defaults_[column_index_ - offset_].length());
+                                parser.parse_some(*visitor_);
+                                parser.finish_parse(*visitor_);
+                            }
+                            else
+                            {
+                                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                            }
+                        }
+                    }
+                    break;
+                case csv_column_type::float_t:
+                    {
+                        if (options_.lossless_number())
+                        {
+                            more_ = visitor_->string_value(buffer_,semantic_tag::bigdec, *this, ec);
+                        }
+                        else
+                        {
+                            std::basic_istringstream<CharT, std::char_traits<CharT>, char_allocator_type> iss{ buffer_ };
+                            double val;
+                            iss >> val;
+                            if (!iss.fail())
+                            {
+                                more_ = visitor_->double_value(val, semantic_tag::none, *this, ec);
+                            }
+                            else
+                            {
+                                if (column_index_ - offset_ < column_defaults_.size() && column_defaults_[column_index_ - offset_].length() > 0)
+                                {
+                                    basic_json_parser<CharT,temp_allocator_type> parser(alloc_);
+                                    parser.update(column_defaults_[column_index_ - offset_].data(),column_defaults_[column_index_ - offset_].length());
+                                    parser.parse_some(*visitor_);
+                                    parser.finish_parse(*visitor_);
+                                }
+                                else
+                                {
+                                    more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                                }
+                            }
+                        }
+                    }
+                    break;
+                case csv_column_type::boolean_t:
+                    {
+                        if (buffer_.length() == 1 && buffer_[0] == '0')
+                        {
+                            more_ = visitor_->bool_value(false, semantic_tag::none, *this, ec);
+                        }
+                        else if (buffer_.length() == 1 && buffer_[0] == '1')
+                        {
+                            more_ = visitor_->bool_value(true, semantic_tag::none, *this, ec);
+                        }
+                        else if (buffer_.length() == 5 && ((buffer_[0] == 'f' || buffer_[0] == 'F') && (buffer_[1] == 'a' || buffer_[1] == 'A') && (buffer_[2] == 'l' || buffer_[2] == 'L') && (buffer_[3] == 's' || buffer_[3] == 'S') && (buffer_[4] == 'e' || buffer_[4] == 'E')))
+                        {
+                            more_ = visitor_->bool_value(false, semantic_tag::none, *this, ec);
+                        }
+                        else if (buffer_.length() == 4 && ((buffer_[0] == 't' || buffer_[0] == 'T') && (buffer_[1] == 'r' || buffer_[1] == 'R') && (buffer_[2] == 'u' || buffer_[2] == 'U') && (buffer_[3] == 'e' || buffer_[3] == 'E')))
+                        {
+                            more_ = visitor_->bool_value(true, semantic_tag::none, *this, ec);
+                        }
+                        else
+                        {
+                            if (column_index_ - offset_ < column_defaults_.size() && column_defaults_[column_index_ - offset_].length() > 0)
+                            {
+                                basic_json_parser<CharT,temp_allocator_type> parser(alloc_);
+                                parser.update(column_defaults_[column_index_ - offset_].data(),column_defaults_[column_index_ - offset_].length());
+                                parser.parse_some(*visitor_);
+                                parser.finish_parse(*visitor_);
+                            }
+                            else
+                            {
+                                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                            }
+                        }
+                    }
+                    break;
+                default:
+                    if (buffer_.length() > 0)
+                    {
+                        more_ = visitor_->string_value(buffer_, semantic_tag::none, *this, ec);
+                    }
+                    else
+                    {
+                        if (column_index_ < column_defaults_.size() + offset_ && column_defaults_[column_index_ - offset_].length() > 0)
+                        {
+                            basic_json_parser<CharT,temp_allocator_type> parser(alloc_);
+                            parser.update(column_defaults_[column_index_ - offset_].data(),column_defaults_[column_index_ - offset_].length());
+                            parser.parse_some(*visitor_);
+                            parser.finish_parse(*visitor_);
+                        }
+                        else
+                        {
+                            more_ = visitor_->string_value(string_view_type(), semantic_tag::none, *this, ec);
+                        }
+                    }
+                    break;  
+            }
+        }
+        else
+        {
+            if (infer_types)
+            {
+                end_value_with_numeric_check(ec);
+            }
+            else
+            {
+                more_ = visitor_->string_value(buffer_, semantic_tag::none, *this, ec);
+            }
+        }
+    }
+
+    enum class numeric_check_state 
+    {
+        initial,
+        null,
+        boolean_true,
+        boolean_false,
+        minus,
+        zero,
+        integer,
+        fraction1,
+        fraction,
+        exp1,
+        exp,
+        not_a_number
+    };
+
+    /*
+        xxx_value 
+    */
+    void end_value_with_numeric_check(std::error_code& ec)
+    {
+        numeric_check_state state = numeric_check_state::initial;
+        bool is_negative = false;
+        int precision = 0;
+        uint8_t decimal_places = 0;
+
+        auto last = buffer_.end();
+
+        std::string buffer;
+        for (auto p = buffer_.begin(); state != numeric_check_state::not_a_number && p != last; ++p)
+        {
+            switch (state)
+            {
+                case numeric_check_state::initial:
+                {
+                    switch (*p)
+                    {
+                    case 'n':case 'N':
+                        if ((last-p) == 4 && (p[1] == 'u' || p[1] == 'U') && (p[2] == 'l' || p[2] == 'L') && (p[3] == 'l' || p[3] == 'L'))
+                        {
+                            state = numeric_check_state::null;
+                        }
+                        else
+                        {
+                            state = numeric_check_state::not_a_number;
+                        }
+                        break;
+                    case 't':case 'T':
+                        if ((last-p) == 4 && (p[1] == 'r' || p[1] == 'R') && (p[2] == 'u' || p[2] == 'U') && (p[3] == 'e' || p[3] == 'U'))
+                        {
+                            state = numeric_check_state::boolean_true;
+                        }
+                        else
+                        {
+                            state = numeric_check_state::not_a_number;
+                        }
+                        break;
+                    case 'f':case 'F':
+                        if ((last-p) == 5 && (p[1] == 'a' || p[1] == 'A') && (p[2] == 'l' || p[2] == 'L') && (p[3] == 's' || p[3] == 'S') && (p[4] == 'e' || p[4] == 'E'))
+                        {
+                            state = numeric_check_state::boolean_false;
+                        }
+                        else
+                        {
+                            state = numeric_check_state::not_a_number;
+                        }
+                        break;
+                    case '-':
+                        is_negative = true;
+                        buffer.push_back(*p);
+                        state = numeric_check_state::minus;
+                        break;
+                    case '0':
+                        ++precision;
+                        buffer.push_back(*p);
+                        state = numeric_check_state::zero;
+                        break;
+                    case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        ++precision;
+                        buffer.push_back(*p);
+                        state = numeric_check_state::integer;
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::zero:
+                {
+                    switch (*p)
+                    {
+                    case '.':
+                        buffer.push_back(to_double_.get_decimal_point());
+                        state = numeric_check_state::fraction1;
+                        break;
+                    case 'e':case 'E':
+                        buffer.push_back(*p);
+                        state = numeric_check_state::exp1;
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::integer:
+                {
+                    switch (*p)
+                    {
+                    case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        ++precision;
+                        buffer.push_back(*p);
+                        break;
+                    case '.':
+                        buffer.push_back(to_double_.get_decimal_point());
+                        state = numeric_check_state::fraction1;
+                        break;
+                    case 'e':case 'E':
+                        buffer.push_back(*p);
+                        state = numeric_check_state::exp1;
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::minus:
+                {
+                    switch (*p)
+                    {
+                    case '0':
+                        ++precision;
+                        buffer.push_back(*p);
+                        state = numeric_check_state::zero;
+                        break;
+                    case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        ++precision;
+                        buffer.push_back(*p);
+                        state = numeric_check_state::integer;
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::fraction1:
+                {
+                    switch (*p)
+                    {
+                    case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        ++precision;
+                        ++decimal_places;
+                        buffer.push_back(*p);
+                        state = numeric_check_state::fraction;
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::fraction:
+                {
+                    switch (*p)
+                    {
+                    case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        ++precision;
+                        ++decimal_places;
+                        buffer.push_back(*p);
+                        break;
+                    case 'e':case 'E':
+                        buffer.push_back(*p);
+                        state = numeric_check_state::exp1;
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::exp1:
+                {
+                    switch (*p)
+                    {
+                    case '-':
+                        buffer.push_back(*p);
+                        break;
+                    case '+':
+                        break;
+                    case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        state = numeric_check_state::exp;
+                        buffer.push_back(*p);
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                case numeric_check_state::exp:
+                {
+                    switch (*p)
+                    {
+                    case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                        buffer.push_back(*p);
+                        break;
+                    default:
+                        state = numeric_check_state::not_a_number;
+                        break;
+                    }
+                    break;
+                }
+                default:
+                    break;
+            }
+        }
+
+        switch (state)
+        {
+            case numeric_check_state::null:
+                more_ = visitor_->null_value(semantic_tag::none, *this, ec);
+                break;
+            case numeric_check_state::boolean_true:
+                more_ = visitor_->bool_value(true, semantic_tag::none, *this, ec);
+                break;
+            case numeric_check_state::boolean_false:
+                more_ = visitor_->bool_value(false, semantic_tag::none, *this, ec);
+                break;
+            case numeric_check_state::zero:
+            case numeric_check_state::integer:
+            {
+                if (is_negative)
+                {
+                    int64_t val{ 0 };
+                    auto result = jsoncons::detail::to_integer_decimal(buffer_.data(), buffer_.length(), val);
+                    if (result)
+                    {
+                        more_ = visitor_->int64_value(val, semantic_tag::none, *this, ec);
+                    }
+                    else // Must be overflow
+                    {
+                        more_ = visitor_->string_value(buffer_, semantic_tag::bigint, *this, ec);
+                    }
+                }
+                else
+                {
+                    uint64_t val{ 0 };
+                    auto result = jsoncons::detail::to_integer_decimal(buffer_.data(), buffer_.length(), val);
+                    if (result)
+                    {
+                        more_ = visitor_->uint64_value(val, semantic_tag::none, *this, ec);
+                    }
+                    else if (result.ec == jsoncons::detail::to_integer_errc::overflow)
+                    {
+                        more_ = visitor_->string_value(buffer_, semantic_tag::bigint, *this, ec);
+                    }
+                    else
+                    {
+                        ec = result.ec;
+                        more_ = false;
+                        return;
+                    }
+                }
+                break;
+            }
+            case numeric_check_state::fraction:
+            case numeric_check_state::exp:
+            {
+                if (options_.lossless_number())
+                {
+                    more_ = visitor_->string_value(buffer_,semantic_tag::bigdec, *this, ec);
+                }
+                else
+                {
+                    double d = to_double_(buffer.c_str(), buffer.length());
+                    more_ = visitor_->double_value(d, semantic_tag::none, *this, ec);
+                }
+                break;
+            }
+            default:
+            {
+                more_ = visitor_->string_value(buffer_, semantic_tag::none, *this, ec);
+                break;
+            }
+        }
+    } 
+
+    void push_state(csv_parse_state state)
+    {
+        state_stack_.push_back(state);
+    }
+
+    csv_parse_state pop_state()
+    {
+        JSONCONS_ASSERT(!state_stack_.empty())
+        csv_parse_state state = state_stack_.back();
+        state_stack_.pop_back();
+        return state;
+    }
+};
+
+using csv_parser = basic_csv_parser<char>;
+using wcsv_parser = basic_csv_parser<wchar_t>;
+
+}}
+
+#endif
+
diff --git a/include/jsoncons_ext/csv/csv_reader.hpp b/include/jsoncons_ext/csv/csv_reader.hpp
new file mode 100644
index 0000000..f10211a
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_reader.hpp
@@ -0,0 +1,348 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_READER_HPP
+#define JSONCONS_CSV_CSV_READER_HPP
+
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <memory> // std::allocator
+#include <utility> // std::move
+#include <istream> // std::basic_istream
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons_ext/csv/csv_error.hpp>
+#include <jsoncons_ext/csv/csv_parser.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons/json_reader.hpp>
+#include <jsoncons/json_decoder.hpp>
+#include <jsoncons/source_adaptor.hpp>
+#include <jsoncons_ext/csv/csv_options.hpp>
+
+namespace jsoncons { namespace csv {
+
+    template<class CharT,class Source=jsoncons::stream_source<CharT>,class Allocator=std::allocator<char>>
+    class basic_csv_reader 
+    {
+        struct stack_item
+        {
+            stack_item() noexcept
+               : array_begun_(false)
+            {
+            }
+
+            bool array_begun_;
+        };
+        using char_type = CharT;
+        using temp_allocator_type = Allocator;
+        typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<CharT> char_allocator_type;
+
+        basic_csv_reader(const basic_csv_reader&) = delete; 
+        basic_csv_reader& operator = (const basic_csv_reader&) = delete; 
+
+        basic_default_json_visitor<CharT> default_visitor_;
+        text_source_adaptor<Source> source_;
+        basic_json_visitor<CharT>& visitor_;
+        basic_csv_parser<CharT,Allocator> parser_;
+
+    public:
+        // Structural characters
+        static constexpr size_t default_max_buffer_size = 16384;
+        //!  Parse an input stream of CSV text into a json object
+        /*!
+          \param is The input stream to read from
+        */
+
+        template <class Sourceable>
+        basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor, 
+                         const Allocator& alloc = Allocator())
+
+           : basic_csv_reader(std::forward<Sourceable>(source), 
+                              visitor, 
+                              basic_csv_decode_options<CharT>(), 
+                              default_csv_parsing(), 
+                              alloc)
+        {
+        }
+
+        template <class Sourceable>
+        basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         const basic_csv_decode_options<CharT>& options, 
+                         const Allocator& alloc = Allocator())
+
+            : basic_csv_reader(std::forward<Sourceable>(source), 
+                               visitor, 
+                               options, 
+                               default_csv_parsing(),
+                               alloc)
+        {
+        }
+
+        template <class Sourceable>
+        basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         std::function<bool(csv_errc,const ser_context&)> err_handler, 
+                         const Allocator& alloc = Allocator())
+            : basic_csv_reader(std::forward<Sourceable>(source), 
+                               visitor, 
+                               basic_csv_decode_options<CharT>(), 
+                               err_handler,
+                               alloc)
+        {
+        }
+
+        template <class Sourceable>
+        basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         const basic_csv_decode_options<CharT>& options,
+                         std::function<bool(csv_errc,const ser_context&)> err_handler, 
+                         const Allocator& alloc = Allocator())
+           : source_(std::forward<Sourceable>(source)),
+             visitor_(visitor),
+             parser_(options, err_handler, alloc)
+             
+        {
+        }
+
+        ~basic_csv_reader() noexcept = default;
+
+        void read()
+        {
+            std::error_code ec;
+            read(ec);
+            if (ec)
+            {
+                JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+            }
+        }
+
+        void read(std::error_code& ec)
+        {
+            read_internal(ec);
+        }
+
+        std::size_t line() const
+        {
+            return parser_.line();
+        }
+
+        std::size_t column() const
+        {
+            return parser_.column();
+        }
+
+        bool eof() const
+        {
+            return parser_.source_exhausted() && source_.eof();
+        }
+
+    private:
+
+        void read_internal(std::error_code& ec)
+        {
+            if (source_.is_error())
+            {
+                ec = csv_errc::source_error;
+                return;
+            }   
+            while (!parser_.stopped())
+            {
+                if (parser_.source_exhausted())
+                {
+                    auto s = source_.read_buffer(ec);
+                    if (ec) return;
+                    if (s.size() > 0)
+                    {
+                        parser_.update(s.data(),s.size());
+                    }
+                }
+                parser_.parse_some(visitor_, ec);
+                if (ec) return;
+            }
+        }
+    };
+
+    template<class CharT,class Source=jsoncons::stream_source<CharT>,class Allocator=std::allocator<char>>
+    class legacy_basic_csv_reader 
+    {
+        struct stack_item
+        {
+            stack_item() noexcept
+               : array_begun_(false)
+            {
+            }
+
+            bool array_begun_;
+        };
+        using char_type = CharT;
+        using temp_allocator_type = Allocator;
+        typedef typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<CharT> char_allocator_type;
+
+        legacy_basic_csv_reader(const legacy_basic_csv_reader&) = delete; 
+        legacy_basic_csv_reader& operator = (const legacy_basic_csv_reader&) = delete; 
+
+        basic_default_json_visitor<CharT> default_visitor_;
+        text_source_adaptor<Source> source_;
+        basic_json_visitor<CharT>& visitor_;
+        basic_csv_parser<CharT,Allocator> parser_;
+
+    public:
+        // Structural characters
+        static constexpr size_t default_max_buffer_size = 16384;
+        //!  Parse an input stream of CSV text into a json object
+        /*!
+          \param is The input stream to read from
+        */
+
+        template <class Sourceable>
+        legacy_basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor, 
+                         const Allocator& alloc = Allocator())
+
+           : legacy_basic_csv_reader(std::forward<Sourceable>(source), 
+                              visitor, 
+                              basic_csv_decode_options<CharT>(), 
+                              default_csv_parsing(), 
+                              alloc)
+        {
+        }
+
+        template <class Sourceable>
+        legacy_basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         const basic_csv_decode_options<CharT>& options, 
+                         const Allocator& alloc = Allocator())
+
+            : legacy_basic_csv_reader(std::forward<Sourceable>(source), 
+                               visitor, 
+                               options, 
+                               default_csv_parsing(),
+                               alloc)
+        {
+        }
+
+        template <class Sourceable>
+        legacy_basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         std::function<bool(csv_errc,const ser_context&)> err_handler, 
+                         const Allocator& alloc = Allocator())
+            : legacy_basic_csv_reader(std::forward<Sourceable>(source), 
+                               visitor, 
+                               basic_csv_decode_options<CharT>(), 
+                               err_handler,
+                               alloc)
+        {
+        }
+
+        template <class Sourceable>
+        legacy_basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         const basic_csv_decode_options<CharT>& options,
+                         std::function<bool(csv_errc,const ser_context&)> err_handler, 
+                         const Allocator& alloc = Allocator(),
+                         typename std::enable_if<!std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type* = 0)
+           : source_(std::forward<Sourceable>(source)),
+             visitor_(visitor),
+             parser_(options, err_handler, alloc)
+        {
+        }
+
+        template <class Sourceable>
+        legacy_basic_csv_reader(Sourceable&& source,
+                         basic_json_visitor<CharT>& visitor,
+                         const basic_csv_decode_options<CharT>& options,
+                         std::function<bool(csv_errc,const ser_context&)> err_handler, 
+                         const Allocator& alloc = Allocator(),
+                         typename std::enable_if<std::is_constructible<jsoncons::basic_string_view<CharT>,Sourceable>::value>::type* = 0)
+           : source_(),
+             visitor_(visitor),
+             parser_(options, err_handler, alloc)             
+        {
+            jsoncons::basic_string_view<CharT> sv(std::forward<Sourceable>(source));
+            auto r = unicode_traits::detect_encoding_from_bom(sv.data(), sv.size());
+            if (!(r.encoding == unicode_traits::encoding_kind::utf8 || r.encoding == unicode_traits::encoding_kind::undetected))
+            {
+                JSONCONS_THROW(ser_error(json_errc::illegal_unicode_character,parser_.line(),parser_.column()));
+            }
+            std::size_t offset = (r.ptr - sv.data());
+            parser_.update(sv.data()+offset,sv.size()-offset);
+        }
+
+        ~legacy_basic_csv_reader() noexcept = default;
+
+        void read()
+        {
+            std::error_code ec;
+            read(ec);
+            if (ec)
+            {
+                JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+            }
+        }
+
+        void read(std::error_code& ec)
+        {
+            read_internal(ec);
+        }
+
+        std::size_t line() const
+        {
+            return parser_.line();
+        }
+
+        std::size_t column() const
+        {
+            return parser_.column();
+        }
+
+        bool eof() const
+        {
+            return parser_.source_exhausted() && source_.eof();
+        }
+
+    private:
+
+        void read_internal(std::error_code& ec)
+        {
+            if (source_.is_error())
+            {
+                ec = csv_errc::source_error;
+                return;
+            }   
+            while (!parser_.stopped())
+            {
+                if (parser_.source_exhausted())
+                {
+                    auto s = source_.read_buffer(ec);
+                    if (ec) return;
+                    if (s.size() > 0)
+                    {
+                        parser_.update(s.data(),s.size());
+                    }
+                }
+                parser_.parse_some(visitor_, ec);
+                if (ec) return;
+            }
+        }
+    };
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+    using csv_reader = legacy_basic_csv_reader<char>;
+    using wcsv_reader = legacy_basic_csv_reader<wchar_t>;
+#endif
+
+    using csv_string_reader = basic_csv_reader<char,string_source<char>>;
+    using wcsv_string_reader = basic_csv_reader<wchar_t,string_source<wchar_t>>;
+    using csv_stream_reader = basic_csv_reader<char,stream_source<char>>;
+    using wcsv_stream_reader = basic_csv_reader<wchar_t,stream_source<wchar_t>>;
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/csv/csv_serializer.hpp b/include/jsoncons_ext/csv/csv_serializer.hpp
new file mode 100644
index 0000000..ec73510
--- /dev/null
+++ b/include/jsoncons_ext/csv/csv_serializer.hpp
@@ -0,0 +1,12 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_CSV_SERIALIZER_HPP
+#define JSONCONS_CSV_CSV_SERIALIZER_HPP
+
+#include <jsoncons_ext/csv/csv_encoder.hpp>
+
+#endif
diff --git a/include/jsoncons_ext/csv/decode_csv.hpp b/include/jsoncons_ext/csv/decode_csv.hpp
new file mode 100644
index 0000000..b91c58b
--- /dev/null
+++ b/include/jsoncons_ext/csv/decode_csv.hpp
@@ -0,0 +1,208 @@
+/// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_DECODE_CSV_HPP
+#define JSONCONS_CSV_DECODE_CSV_HPP
+
+#include <jsoncons_ext/csv/csv_options.hpp>
+#include <jsoncons_ext/csv/csv_reader.hpp>
+#include <jsoncons_ext/csv/csv_encoder.hpp>
+#include <jsoncons_ext/csv/csv_cursor.hpp>
+
+namespace jsoncons { 
+namespace csv {
+
+    template <class T,class Source>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_sequence_of<Source,typename T::char_type>::value,T>::type 
+    decode_csv(const Source& s, const basic_csv_decode_options<typename Source::value_type>& options = basic_csv_decode_options<typename Source::value_type>())
+    {
+        using char_type = typename Source::value_type;
+
+        json_decoder<T> decoder;
+
+        basic_csv_reader<char_type,jsoncons::string_source<char_type>> reader(s,decoder,options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template <class T,class Source>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_char_sequence<Source>::value,T>::type 
+    decode_csv(const Source& s, const basic_csv_decode_options<typename Source::value_type>& options = basic_csv_decode_options<typename Source::value_type>())
+    {
+        using char_type = typename Source::value_type;
+
+        basic_csv_cursor<char_type> cursor(s, options);
+        jsoncons::json_decoder<basic_json<char_type>> decoder;
+
+        std::error_code ec;
+        T val = decode_traits<T,char_type>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template <class T,class CharT>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_csv(std::basic_istream<CharT>& is, const basic_csv_decode_options<CharT>& options = basic_csv_decode_options<CharT>())
+    {
+        using char_type = CharT;
+
+        json_decoder<T> decoder;
+
+        basic_csv_reader<char_type,jsoncons::stream_source<char_type>> reader(is,decoder,options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template <class T,class CharT>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_csv(std::basic_istream<CharT>& is, const basic_csv_decode_options<CharT>& options = basic_csv_decode_options<CharT>())
+    {
+        basic_csv_cursor<CharT> cursor(is, options);
+        jsoncons::json_decoder<basic_json<CharT>> decoder;
+
+        std::error_code ec;
+        T val = decode_traits<T,CharT>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template <class T, class InputIt>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type
+    decode_csv(InputIt first, InputIt last,
+                const basic_csv_decode_options<typename std::iterator_traits<InputIt>::value_type>& options = 
+                    basic_csv_decode_options<typename std::iterator_traits<InputIt>::value_type>())
+    {
+        using char_type = typename std::iterator_traits<InputIt>::value_type;
+
+        jsoncons::json_decoder<T> decoder;
+        basic_csv_reader<char_type, iterator_source<InputIt>> reader(iterator_source<InputIt>(first,last), decoder, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template <class T, class InputIt>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type
+    decode_csv(InputIt first, InputIt last,
+               const basic_csv_decode_options<typename std::iterator_traits<InputIt>::value_type>& options = 
+                    basic_csv_decode_options<typename std::iterator_traits<InputIt>::value_type>())
+    {
+        using char_type = typename std::iterator_traits<InputIt>::value_type;
+
+        basic_csv_cursor<char_type,iterator_source<InputIt>> cursor(iterator_source<InputIt>(first, last), options);
+        jsoncons::json_decoder<basic_json<char_type>> decoder;
+        std::error_code ec;
+        T val = decode_traits<T,char_type>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    // With leading allocator parameter
+
+    template <class T,class Source,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_sequence_of<Source,typename T::char_type>::value,T>::type 
+    decode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               const Source& s, 
+               const basic_csv_decode_options<typename Source::value_type>& options = basic_csv_decode_options<typename Source::value_type>())
+    {
+        using char_type = typename Source::value_type;
+
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+
+        basic_csv_reader<char_type,jsoncons::string_source<char_type>,TempAllocator> reader(s,decoder,options,temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template <class T,class Source,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_char_sequence<Source>::value,T>::type 
+    decode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               const Source& s, 
+               const basic_csv_decode_options<typename Source::value_type>& options = basic_csv_decode_options<typename Source::value_type>())
+    {
+        using char_type = typename Source::value_type;
+
+        basic_csv_cursor<char_type,stream_source<char_type>,TempAllocator> cursor(s, options, temp_alloc);
+        json_decoder<basic_json<char_type,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char_type>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template <class T,class CharT,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               std::basic_istream<CharT>& is, 
+               const basic_csv_decode_options<CharT>& options = basic_csv_decode_options<CharT>())
+    {
+        using char_type = CharT;
+
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+
+        basic_csv_reader<char_type,jsoncons::string_source<char_type>,TempAllocator> reader(is,decoder,options,temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template <class T,class CharT,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               std::basic_istream<CharT>& is, 
+               const basic_csv_decode_options<CharT>& options = basic_csv_decode_options<CharT>())
+    {
+        basic_csv_cursor<CharT,stream_source<CharT>,TempAllocator> cursor(is, options, temp_alloc);
+        json_decoder<basic_json<CharT,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,CharT>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+} // namespace csv 
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/csv/encode_csv.hpp b/include/jsoncons_ext/csv/encode_csv.hpp
new file mode 100644
index 0000000..d919253
--- /dev/null
+++ b/include/jsoncons_ext/csv/encode_csv.hpp
@@ -0,0 +1,122 @@
+/// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_CSV_ENCODE_CSV_HPP
+#define JSONCONS_CSV_ENCODE_CSV_HPP
+
+#include <jsoncons_ext/csv/csv_options.hpp>
+#include <jsoncons_ext/csv/csv_reader.hpp>
+#include <jsoncons_ext/csv/csv_encoder.hpp>
+
+namespace jsoncons { 
+namespace csv {
+
+    template <class T,class Container>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_char_container<Container>::value>::type 
+    encode_csv(const T& j, Container& s, const basic_csv_encode_options<typename Container::value_type>& options = basic_csv_encode_options<typename Container::value_type>())
+    {
+        using char_type = typename Container::value_type;
+        basic_csv_encoder<char_type,jsoncons::string_sink<std::basic_string<char_type>>> encoder(s,options);
+        j.dump(encoder);
+    }
+
+    template <class T,class Container>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_char_container<Container>::value>::type 
+    encode_csv(const T& val, Container& s, const basic_csv_encode_options<typename Container::value_type>& options = basic_csv_encode_options<typename Container::value_type>())
+    {
+        using char_type = typename Container::value_type;
+        basic_csv_encoder<char_type,jsoncons::string_sink<std::basic_string<char_type>>> encoder(s,options);
+        std::error_code ec;
+        encode_traits<T,char_type>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template <class T, class CharT>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_csv(const T& j, std::basic_ostream<CharT>& os, const basic_csv_encode_options<CharT>& options = basic_csv_encode_options<CharT>())
+    {
+        using char_type = CharT;
+        basic_csv_encoder<char_type,jsoncons::stream_sink<char_type>> encoder(os,options);
+        j.dump(encoder);
+    }
+
+    template <class T, class CharT>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_csv(const T& val, std::basic_ostream<CharT>& os, const basic_csv_encode_options<CharT>& options = basic_csv_encode_options<CharT>())
+    {
+        using char_type = CharT;
+        basic_csv_encoder<char_type,jsoncons::stream_sink<char_type>> encoder(os,options);
+        std::error_code ec;
+        encode_traits<T,CharT>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    // with temp_allocator_arg_t
+
+    template <class T, class Container, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_char_container<Container>::value>::type 
+    encode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               const T& j, Container& s, const basic_csv_encode_options<typename Container::value_type>& options = basic_csv_encode_options<typename Container::value_type>())
+    {
+        using char_type = typename Container::value_type;
+        basic_csv_encoder<char_type,jsoncons::string_sink<std::basic_string<char_type>>,TempAllocator> encoder(s, options, temp_alloc);
+        j.dump(encoder);
+    }
+
+    template <class T, class Container, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_char_container<Container>::value>::type 
+    encode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               const T& val, Container& s, const basic_csv_encode_options<typename Container::value_type>& options = basic_csv_encode_options<typename Container::value_type>())
+    {
+        using char_type = typename Container::value_type;
+        basic_csv_encoder<char_type,jsoncons::string_sink<std::basic_string<char_type>>,TempAllocator> encoder(s, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char_type>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template <class T, class CharT, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               const T& j, std::basic_ostream<CharT>& os, const basic_csv_encode_options<CharT>& options = basic_csv_encode_options<CharT>())
+    {
+        using char_type = CharT;
+        basic_csv_encoder<char_type,jsoncons::stream_sink<char_type>,TempAllocator> encoder(os, options, temp_alloc);
+        j.dump(encoder);
+    }
+
+    template <class T, class CharT, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_csv(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+               const T& val, std::basic_ostream<CharT>& os, const basic_csv_encode_options<CharT>& options = basic_csv_encode_options<CharT>())
+    {
+        using char_type = CharT;
+        basic_csv_encoder<char_type,jsoncons::stream_sink<char_type>,TempAllocator> encoder(os, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,CharT>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+} // namespace csv 
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jmespath/jmespath.hpp b/include/jsoncons_ext/jmespath/jmespath.hpp
new file mode 100644
index 0000000..69458cd
--- /dev/null
+++ b/include/jsoncons_ext/jmespath/jmespath.hpp
@@ -0,0 +1,5215 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JMESPATH_JMESPATH_HPP
+#define JSONCONS_JMESPATH_JMESPATH_HPP
+
+#include <string>
+#include <vector>
+#include <unordered_map> // std::unordered_map
+#include <memory>
+#include <type_traits> // std::is_const
+#include <limits> // std::numeric_limits
+#include <utility> // std::move
+#include <functional> // 
+#include <algorithm> // std::stable_sort, std::reverse
+#include <cmath> // std::abs
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jmespath/jmespath_error.hpp>
+
+namespace jsoncons { 
+namespace jmespath {
+
+    enum class operator_kind
+    {
+        default_op, // Identifier, CurrentNode, Index, MultiSelectList, MultiSelectHash, FunctionExpression
+        projection_op,
+        flatten_projection_op, // FlattenProjection
+        or_op,
+        and_op,
+        eq_op,
+        ne_op,
+        lt_op,
+        lte_op,
+        gt_op,
+        gte_op,
+        not_op
+    };
+
+    struct operator_table final
+    {
+        static int precedence_level(operator_kind oper)
+        {
+            switch (oper)
+            {
+                case operator_kind::projection_op:
+                    return 11;
+                case operator_kind::flatten_projection_op:
+                    return 11;
+                case operator_kind::or_op:
+                    return 9;
+                case operator_kind::and_op:
+                    return 8;
+                case operator_kind::eq_op:
+                case operator_kind::ne_op:
+                    return 6;
+                case operator_kind::lt_op:
+                case operator_kind::lte_op:
+                case operator_kind::gt_op:
+                case operator_kind::gte_op:
+                    return 5;
+                case operator_kind::not_op:
+                    return 1;
+                default:
+                    return 1;
+            }
+        }
+
+        static bool is_right_associative(operator_kind oper)
+        {
+            switch (oper)
+            {
+                case operator_kind::not_op:
+                    return true;
+                case operator_kind::projection_op:
+                    return true;
+                case operator_kind::flatten_projection_op:
+                    return false;
+                case operator_kind::or_op:
+                case operator_kind::and_op:
+                case operator_kind::eq_op:
+                case operator_kind::ne_op:
+                case operator_kind::lt_op:
+                case operator_kind::lte_op:
+                case operator_kind::gt_op:
+                case operator_kind::gte_op:
+                    return false;
+                default:
+                    return false;
+            }
+        }
+    };
+
+    enum class token_kind 
+    {
+        current_node,
+        lparen,
+        rparen,
+        begin_multi_select_hash,
+        end_multi_select_hash,
+        begin_multi_select_list,
+        end_multi_select_list,
+        begin_filter,
+        end_filter,
+        pipe,
+        separator,
+        key,
+        literal,
+        expression,
+        binary_operator,
+        unary_operator,
+        function,
+        end_function,
+        argument,
+        begin_expression_type,
+        end_expression_type,
+        end_of_expression
+    };
+
+    struct literal_arg_t
+    {
+        explicit literal_arg_t() = default;
+    };
+    constexpr literal_arg_t literal_arg{};
+
+    struct begin_expression_type_arg_t
+    {
+        explicit begin_expression_type_arg_t() = default;
+    };
+    constexpr begin_expression_type_arg_t begin_expression_type_arg{};
+
+    struct end_expression_type_arg_t
+    {
+        explicit end_expression_type_arg_t() = default;
+    };
+    constexpr end_expression_type_arg_t end_expression_type_arg{};
+
+    struct end_of_expression_arg_t
+    {
+        explicit end_of_expression_arg_t() = default;
+    };
+    constexpr end_of_expression_arg_t end_of_expression_arg{};
+
+    struct separator_arg_t
+    {
+        explicit separator_arg_t() = default;
+    };
+    constexpr separator_arg_t separator_arg{};
+
+    struct key_arg_t
+    {
+        explicit key_arg_t() = default;
+    };
+    constexpr key_arg_t key_arg{};
+
+    struct lparen_arg_t
+    {
+        explicit lparen_arg_t() = default;
+    };
+    constexpr lparen_arg_t lparen_arg{};
+
+    struct rparen_arg_t
+    {
+        explicit rparen_arg_t() = default;
+    };
+    constexpr rparen_arg_t rparen_arg{};
+
+    struct begin_multi_select_hash_arg_t
+    {
+        explicit begin_multi_select_hash_arg_t() = default;
+    };
+    constexpr begin_multi_select_hash_arg_t begin_multi_select_hash_arg{};
+
+    struct end_multi_select_hash_arg_t
+    {
+        explicit end_multi_select_hash_arg_t() = default;
+    };
+    constexpr end_multi_select_hash_arg_t end_multi_select_hash_arg{};
+
+    struct begin_multi_select_list_arg_t
+    {
+        explicit begin_multi_select_list_arg_t() = default;
+    };
+    constexpr begin_multi_select_list_arg_t begin_multi_select_list_arg{};
+
+    struct end_multi_select_list_arg_t
+    {
+        explicit end_multi_select_list_arg_t() = default;
+    };
+    constexpr end_multi_select_list_arg_t end_multi_select_list_arg{};
+
+    struct begin_filter_arg_t
+    {
+        explicit begin_filter_arg_t() = default;
+    };
+    constexpr begin_filter_arg_t begin_filter_arg{};
+
+    struct end_filter_arg_t
+    {
+        explicit end_filter_arg_t() = default;
+    };
+    constexpr end_filter_arg_t end_filter_arg{};
+
+    struct pipe_arg_t
+    {
+        explicit pipe_arg_t() = default;
+    };
+    constexpr pipe_arg_t pipe_arg{};
+
+    struct current_node_arg_t
+    {
+        explicit current_node_arg_t() = default;
+    };
+    constexpr current_node_arg_t current_node_arg{};
+
+    struct end_function_arg_t
+    {
+        explicit end_function_arg_t() = default;
+    };
+    constexpr end_function_arg_t end_function_arg{};
+
+    struct argument_arg_t
+    {
+        explicit argument_arg_t() = default;
+    };
+    constexpr argument_arg_t argument_arg{};
+
+    struct slice
+    {
+        jsoncons::optional<int64_t> start_;
+        jsoncons::optional<int64_t> stop_;
+        int64_t step_;
+
+        slice()
+            : start_(), stop_(), step_(1)
+        {
+        }
+
+        slice(const jsoncons::optional<int64_t>& start, const jsoncons::optional<int64_t>& end, int64_t step) 
+            : start_(start), stop_(end), step_(step)
+        {
+        }
+
+        slice(const slice& other)
+            : start_(other.start_), stop_(other.stop_), step_(other.step_)
+        {
+        }
+
+        slice& operator=(const slice& rhs) 
+        {
+            if (this != &rhs)
+            {
+                if (rhs.start_)
+                {
+                    start_ = rhs.start_;
+                }
+                else
+                {
+                    start_.reset();
+                }
+                if (rhs.stop_)
+                {
+                    stop_ = rhs.stop_;
+                }
+                else
+                {
+                    stop_.reset();
+                }
+                step_ = rhs.step_;
+            }
+            return *this;
+        }
+
+        int64_t get_start(std::size_t size) const
+        {
+            if (start_)
+            {
+                auto len = *start_ >= 0 ? *start_ : (static_cast<int64_t>(size) + *start_);
+                return len <= static_cast<int64_t>(size) ? len : static_cast<int64_t>(size);
+            }
+            else
+            {
+                if (step_ >= 0)
+                {
+                    return 0;
+                }
+                else 
+                {
+                    return static_cast<int64_t>(size);
+                }
+            }
+        }
+
+        int64_t get_stop(std::size_t size) const
+        {
+            if (stop_)
+            {
+                auto len = *stop_ >= 0 ? *stop_ : (static_cast<int64_t>(size) + *stop_);
+                return len <= static_cast<int64_t>(size) ? len : static_cast<int64_t>(size);
+            }
+            else
+            {
+                return step_ >= 0 ? static_cast<int64_t>(size) : -1;
+            }
+        }
+
+        int64_t step() const
+        {
+            return step_; // Allow negative
+        }
+    };
+
+    namespace detail {
+     
+    enum class path_state 
+    {
+        start,
+        lhs_expression,
+        rhs_expression,
+        sub_expression,
+        expression_type,
+        comparator_expression,
+        function_expression,
+        argument,
+        expression_or_expression_type,
+        quoted_string,
+        raw_string,
+        raw_string_escape_char,
+        quoted_string_escape_char,
+        escape_u1, 
+        escape_u2, 
+        escape_u3, 
+        escape_u4, 
+        escape_expect_surrogate_pair1, 
+        escape_expect_surrogate_pair2, 
+        escape_u5, 
+        escape_u6, 
+        escape_u7, 
+        escape_u8, 
+        literal,
+        key_expr,
+        val_expr,
+        identifier_or_function_expr,
+        unquoted_string,
+        key_val_expr,
+        number,
+        digit,
+        index_or_slice_expression,
+        bracket_specifier,
+        bracket_specifier_or_multi_select_list,
+        filter,
+        multi_select_list,
+        multi_select_hash,
+        rhs_slice_expression_stop,
+        rhs_slice_expression_step,
+        expect_rbracket,
+        expect_rparen,
+        expect_dot,
+        expect_rbrace,
+        expect_colon,
+        expect_multi_select_list,
+        cmp_lt_or_lte,
+        cmp_eq,
+        cmp_gt_or_gte,
+        cmp_ne,
+        expect_pipe_or_or,
+        expect_and
+    };
+
+    // dynamic_resources
+
+    template<class Json, class JsonReference>
+    class dynamic_resources
+    {
+        typedef typename Json::char_type char_type;
+        typedef typename Json::char_traits_type char_traits_type;
+        typedef std::basic_string<char_type,char_traits_type> string_type;
+        typedef typename Json::string_view_type string_view_type;
+        typedef JsonReference reference;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        typedef typename Json::const_pointer const_pointer;
+
+        std::vector<std::unique_ptr<Json>> temp_storage_;
+
+    public:
+        ~dynamic_resources()
+        {
+        }
+
+        reference number_type_name() 
+        {
+            static Json number_type_name(JSONCONS_STRING_CONSTANT(char_type, "number"));
+
+            return number_type_name;
+        }
+
+        reference boolean_type_name()
+        {
+            static Json boolean_type_name(JSONCONS_STRING_CONSTANT(char_type, "boolean"));
+
+            return boolean_type_name;
+        }
+
+        reference string_type_name()
+        {
+            static Json string_type_name(JSONCONS_STRING_CONSTANT(char_type, "string"));
+
+            return string_type_name;
+        }
+
+        reference object_type_name()
+        {
+            static Json object_type_name(JSONCONS_STRING_CONSTANT(char_type, "object"));
+
+            return object_type_name;
+        }
+
+        reference array_type_name()
+        {
+            static Json array_type_name(JSONCONS_STRING_CONSTANT(char_type, "array"));
+
+            return array_type_name;
+        }
+
+        reference null_type_name()
+        {
+            static Json null_type_name(JSONCONS_STRING_CONSTANT(char_type, "null"));
+
+            return null_type_name;
+        }
+
+        reference true_value() const
+        {
+            static const Json true_value(true, semantic_tag::none);
+            return true_value;
+        }
+
+        reference false_value() const
+        {
+            static const Json false_value(false, semantic_tag::none);
+            return false_value;
+        }
+
+        reference null_value() const
+        {
+            static const Json null_value(null_type(), semantic_tag::none);
+            return null_value;
+        }
+
+        template <typename... Args>
+        Json* create_json(Args&& ... args)
+        {
+            auto temp = jsoncons::make_unique<Json>(std::forward<Args>(args)...);
+            Json* ptr = temp.get();
+            temp_storage_.emplace_back(std::move(temp));
+            return ptr;
+        }
+    };
+
+    template<class Json, class JsonReference>
+    class jmespath_evaluator 
+    {
+    public:
+        typedef typename Json::char_type char_type;
+        typedef typename Json::char_traits_type char_traits_type;
+        typedef std::basic_string<char_type,char_traits_type> string_type;
+        typedef typename Json::string_view_type string_view_type;
+        typedef JsonReference reference;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        typedef typename Json::const_pointer const_pointer;
+
+        static bool is_false(reference ref)
+        {
+            return (ref.is_array() && ref.empty()) ||
+                   (ref.is_object() && ref.empty()) ||
+                   (ref.is_string() && ref.as_string_view().size() == 0) ||
+                   (ref.is_bool() && !ref.as_bool()) ||
+                   ref.is_null();
+        }
+
+        static bool is_true(reference ref)
+        {
+            return !is_false(ref);
+        }
+
+        class unary_operator
+        {
+            std::size_t precedence_level_;
+            bool is_right_associative_;
+
+        protected:
+            ~unary_operator() = default; // virtual destructor not needed
+        public:
+            unary_operator(operator_kind oper)
+                : precedence_level_(operator_table::precedence_level(oper)), 
+                  is_right_associative_(operator_table::is_right_associative(oper))
+            {
+            }
+
+            std::size_t precedence_level() const 
+            {
+                return precedence_level_;
+            }
+            bool is_right_associative() const
+            {
+                return is_right_associative_;
+            }
+
+            virtual reference evaluate(reference val, dynamic_resources<Json,JsonReference>&, std::error_code& ec) const = 0;
+        };
+
+        class not_expression final : public unary_operator
+        {
+        public:
+            not_expression()
+                : unary_operator(operator_kind::not_op)
+            {}
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                return is_false(val) ? resources.true_value() : resources.false_value();
+            }
+        };
+
+        class binary_operator
+        {
+            std::size_t precedence_level_;
+            bool is_right_associative_;
+        protected:
+            ~binary_operator() = default; // virtual destructor not needed
+        public:
+            binary_operator(operator_kind oper)
+                : precedence_level_(operator_table::precedence_level(oper)), 
+                  is_right_associative_(operator_table::is_right_associative(oper))
+            {
+            }
+
+
+            std::size_t precedence_level() const 
+            {
+                return precedence_level_;
+            }
+            bool is_right_associative() const
+            {
+                return is_right_associative_;
+            }
+
+            virtual reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>&, std::error_code& ec) const = 0;
+
+            virtual std::string to_string(std::size_t indent = 0) const
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("to_string not implemented\n");
+                return s;
+            }
+        };
+
+        // expression_base
+        class expression_base
+        {
+            std::size_t precedence_level_;
+            bool is_right_associative_;
+            bool is_projection_;
+        public:
+            expression_base(operator_kind oper, bool is_projection)
+                : precedence_level_(operator_table::precedence_level(oper)), 
+                  is_right_associative_(operator_table::is_right_associative(oper)), 
+                  is_projection_(is_projection)
+            {
+            }
+
+            std::size_t precedence_level() const
+            {
+                return precedence_level_;
+            }
+
+            bool is_right_associative() const
+            {
+                return is_right_associative_;
+            }
+
+            bool is_projection() const 
+            {
+                return is_projection_;
+            }
+
+            virtual ~expression_base() = default;
+
+            virtual reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const = 0;
+
+            virtual void add_expression(std::unique_ptr<expression_base>&& expressions) = 0;
+
+            virtual std::string to_string(std::size_t = 0) const
+            {
+                return std::string("to_string not implemented");
+            }
+        };  
+
+        // parameter
+
+        enum class parameter_kind{value, expression};
+
+        class parameter
+        {
+            parameter_kind type_;
+
+            union
+            {
+                expression_base* expression_;
+                pointer value_;
+            };
+
+        public:
+
+            parameter(const parameter& other) noexcept
+                : type_(other.type_)
+            {
+                switch (type_)
+                {
+                    case parameter_kind::expression:
+                        expression_ = other.expression_;
+                        break;
+                    case parameter_kind::value:
+                        value_ = other.value_;
+                        break;
+                    default:
+                        break;
+                }
+            }
+
+            parameter(reference value) noexcept
+                : type_(parameter_kind::value), value_(std::addressof(value))
+            {
+            }
+
+            parameter(expression_base* expression) noexcept
+                : type_(parameter_kind::expression), expression_(expression)
+            {
+            }
+
+            parameter& operator=(const parameter& other)
+            {
+                if (&other != this)
+                {
+                    type_ = other.type_;
+                    switch (type_)
+                    {
+                        case parameter_kind::expression:
+                            expression_ = other.expression_;
+                            break;
+                        case parameter_kind::value:
+                            value_ = other.value_;
+                            break;
+                        default:
+                            break;
+                    }
+                }
+                return *this;
+            }
+
+            bool is_value() const
+            {
+                return type_ == parameter_kind::value;
+            }
+
+            bool is_expression() const
+            {
+                return type_ == parameter_kind::expression;
+            }
+
+            const Json& value() const
+            {
+                return *value_;
+            }
+
+            const expression_base& expression() const
+            {
+                return *expression_;
+            }
+        };
+
+        // function_base
+        class function_base
+        {
+            jsoncons::optional<std::size_t> arg_count_;
+        public:
+            function_base(jsoncons::optional<std::size_t> arg_count)
+                : arg_count_(arg_count)
+            {
+            }
+
+            jsoncons::optional<std::size_t> arity() const
+            {
+                return arg_count_;
+            }
+
+            virtual ~function_base() = default;
+
+            virtual reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>&, std::error_code& ec) const = 0;
+
+            virtual std::string to_string(std::size_t = 0) const
+            {
+                return std::string("to_string not implemented");
+            }
+        };  
+
+        class abs_function : public function_base
+        {
+        public:
+            abs_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                switch (arg0.type())
+                {
+                    case json_type::uint64_value:
+                        return arg0;
+                    case json_type::int64_value:
+                    {
+                        return arg0.template as<int64_t>() >= 0 ? arg0 : *resources.create_json(std::abs(arg0.template as<int64_t>()));
+                    }
+                    case json_type::double_value:
+                    {
+                        return arg0.template as<double>() >= 0 ? arg0 : *resources.create_json(std::abs(arg0.template as<double>()));
+                    }
+                    default:
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                }
+            }
+        };
+
+        class avg_function : public function_base
+        {
+        public:
+            avg_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.empty())
+                {
+                    return resources.null_value();
+                }
+
+                double sum = 0;
+                for (auto& j : arg0.array_range())
+                {
+                    if (!j.is_number())
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    sum += j.template as<double>();
+                }
+
+                return sum == 0 ? resources.null_value() : *resources.create_json(sum/arg0.size());
+            }
+        };
+
+        class ceil_function : public function_base
+        {
+        public:
+            ceil_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                switch (arg0.type())
+                {
+                    case json_type::uint64_value:
+                    case json_type::int64_value:
+                    {
+                        return *resources.create_json(arg0.template as<double>());
+                    }
+                    case json_type::double_value:
+                    {
+                        return *resources.create_json(std::ceil(arg0.template as<double>()));
+                    }
+                    default:
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                }
+            }
+        };
+
+        class contains_function : public function_base
+        {
+        public:
+            contains_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_value() && args[1].is_value()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+
+                reference arg0 = args[0].value();
+                reference arg1 = args[1].value();
+
+                switch (arg0.type())
+                {
+                    case json_type::array_value:
+                        for (auto& j : arg0.array_range())
+                        {
+                            if (j == arg1)
+                            {
+                                return resources.true_value();
+                            }
+                        }
+                        return resources.false_value();
+                    case json_type::string_value:
+                    {
+                        if (!arg1.is_string())
+                        {
+                            ec = jmespath_errc::invalid_type;
+                            return resources.null_value();
+                        }
+                        auto sv0 = arg0.template as<string_view_type>();
+                        auto sv1 = arg1.template as<string_view_type>();
+                        return sv0.find(sv1) != string_view_type::npos ? resources.true_value() : resources.false_value();
+                    }
+                    default:
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                }
+            }
+        };
+
+        class ends_with_function : public function_base
+        {
+        public:
+            ends_with_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_value() && args[1].is_value()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_string())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg1 = args[1].value();
+                if (!arg1.is_string())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                auto sv0 = arg0.template as<string_view_type>();
+                auto sv1 = arg1.template as<string_view_type>();
+
+                if (sv1.length() <= sv0.length() && sv1 == sv0.substr(sv0.length() - sv1.length()))
+                {
+                    return resources.true_value();
+                }
+                else
+                {
+                    return resources.false_value();
+                }
+            }
+        };
+
+        class floor_function : public function_base
+        {
+        public:
+            floor_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                switch (arg0.type())
+                {
+                    case json_type::uint64_value:
+                    case json_type::int64_value:
+                    {
+                        return *resources.create_json(arg0.template as<double>());
+                    }
+                    case json_type::double_value:
+                    {
+                        return *resources.create_json(std::floor(arg0.template as<double>()));
+                    }
+                    default:
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                }
+            }
+        };
+
+        class join_function : public function_base
+        {
+        public:
+            join_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                reference arg0 = args[0].value();
+                reference arg1 = args[1].value();
+
+                if (!(args[0].is_value() && args[1].is_value()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                if (!arg0.is_string())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (!arg1.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                string_type sep = arg0.template as<string_type>();
+                string_type buf;
+                for (auto& j : arg1.array_range())
+                {
+                    if (!j.is_string())
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    if (!buf.empty())
+                    {
+                        buf.append(sep);
+                    }
+                    auto sv = j.template as<string_view_type>();
+                    buf.append(sv.begin(), sv.end());
+                }
+                return *resources.create_json(buf);
+            }
+        };
+
+        class length_function : public function_base
+        {
+        public:
+            length_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+
+                switch (arg0.type())
+                {
+                    case json_type::object_value:
+                    case json_type::array_value:
+                        return *resources.create_json(arg0.size());
+                    case json_type::string_value:
+                    {
+                        auto sv0 = arg0.template as<string_view_type>();
+                        auto length = unicode_traits::count_codepoints(sv0.data(), sv0.size());
+                        return *resources.create_json(length);
+                    }
+                    default:
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                }
+            }
+        };
+
+        class max_function : public function_base
+        {
+        public:
+            max_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.empty())
+                {
+                    return resources.null_value();
+                }
+
+                bool is_number = arg0.at(0).is_number();
+                bool is_string = arg0.at(0).is_string();
+                if (!is_number && !is_string)
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                std::size_t index = 0;
+                for (std::size_t i = 1; i < arg0.size(); ++i)
+                {
+                    if (!(arg0.at(i).is_number() == is_number && arg0.at(i).is_string() == is_string))
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    if (arg0.at(i) > arg0.at(index))
+                    {
+                        index = i;
+                    }
+                }
+
+                return arg0.at(index);
+            }
+        };
+
+        class max_by_function : public function_base
+        {
+        public:
+            max_by_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_value() && args[1].is_expression()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.empty())
+                {
+                    return resources.null_value();
+                }
+
+                const auto& expr = args[1].expression();
+
+                std::error_code ec2;
+                Json key1 = expr.evaluate(arg0.at(0), resources, ec2); 
+
+                bool is_number = key1.is_number();
+                bool is_string = key1.is_string();
+                if (!(is_number || is_string))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                std::size_t index = 0;
+                for (std::size_t i = 1; i < arg0.size(); ++i)
+                {
+                    reference key2 = expr.evaluate(arg0.at(i), resources, ec2); 
+                    if (!(key2.is_number() == is_number && key2.is_string() == is_string))
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    if (key2 > key1)
+                    {
+                        key1 = key2;
+                        index = i;
+                    }
+                }
+
+                return arg0.at(index);
+            }
+        };
+
+        class map_function : public function_base
+        {
+        public:
+            map_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_expression() && args[1].is_value()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                const auto& expr = args[0].expression();
+
+                reference arg0 = args[1].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+
+                for (auto& item : arg0.array_range())
+                {
+                    auto& j = expr.evaluate(item, resources, ec);
+                    if (ec)
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                }
+
+                return *result;
+            }
+
+            std::string to_string(std::size_t = 0) const override
+            {
+                return std::string("map_function\n");
+            }
+        };
+
+        class min_function : public function_base
+        {
+        public:
+            min_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.empty())
+                {
+                    return resources.null_value();
+                }
+
+                bool is_number = arg0.at(0).is_number();
+                bool is_string = arg0.at(0).is_string();
+                if (!is_number && !is_string)
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                std::size_t index = 0;
+                for (std::size_t i = 1; i < arg0.size(); ++i)
+                {
+                    if (!(arg0.at(i).is_number() == is_number && arg0.at(i).is_string() == is_string))
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    if (arg0.at(i) < arg0.at(index))
+                    {
+                        index = i;
+                    }
+                }
+
+                return arg0.at(index);
+            }
+        };
+
+        class min_by_function : public function_base
+        {
+        public:
+            min_by_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_value() && args[1].is_expression()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.empty())
+                {
+                    return resources.null_value();
+                }
+
+                const auto& expr = args[1].expression();
+
+                std::error_code ec2;
+                Json key1 = expr.evaluate(arg0.at(0), resources, ec2); 
+
+                bool is_number = key1.is_number();
+                bool is_string = key1.is_string();
+                if (!(is_number || is_string))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                std::size_t index = 0;
+                for (std::size_t i = 1; i < arg0.size(); ++i)
+                {
+                    reference key2 = expr.evaluate(arg0.at(i), resources, ec2); 
+                    if (!(key2.is_number() == is_number && key2.is_string() == is_string))
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    if (key2 < key1)
+                    {
+                        key1 = key2;
+                        index = i;
+                    }
+                }
+
+                return arg0.at(index);
+            }
+        };
+
+        class merge_function : public function_base
+        {
+        public:
+            merge_function()
+                : function_base(jsoncons::optional<std::size_t>())
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (args.empty())
+                {
+                    ec = jmespath_errc::invalid_arity;
+                    return resources.null_value();
+                }
+
+                for (auto& param : args)
+                {
+                    if (!param.is_value())
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_object())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (args.size() == 1)
+                {
+                    return arg0;
+                }
+
+                auto result = resources.create_json(arg0);
+                for (std::size_t i = 1; i < args.size(); ++i)
+                {
+                    reference argi = args[i].value();
+                    if (!argi.is_object())
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    for (auto& item : argi.object_range())
+                    {
+                        result->insert_or_assign(item.key(),item.value());
+                    }
+                }
+
+                return *result;
+            }
+        };
+
+        class type_function : public function_base
+        {
+        public:
+            type_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+
+                switch (arg0.type())
+                {
+                    case json_type::int64_value:
+                    case json_type::uint64_value:
+                    case json_type::double_value:
+                        return resources.number_type_name();
+                    case json_type::bool_value:
+                        return resources.boolean_type_name();
+                    case json_type::string_value:
+                        return resources.string_type_name();
+                    case json_type::object_value:
+                        return resources.object_type_name();
+                    case json_type::array_value:
+                        return resources.array_type_name();
+                    default:
+                        return resources.null_type_name();
+                        break;
+
+                }
+            }
+        };
+
+        class sort_function : public function_base
+        {
+        public:
+            sort_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.size() <= 1)
+                {
+                    return arg0;
+                }
+
+                bool is_number = arg0.at(0).is_number();
+                bool is_string = arg0.at(0).is_string();
+                if (!is_number && !is_string)
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                for (std::size_t i = 1; i < arg0.size(); ++i)
+                {
+                    if (arg0.at(i).is_number() != is_number || arg0.at(i).is_string() != is_string)
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                }
+
+                auto v = resources.create_json(arg0);
+                std::stable_sort((v->array_range()).begin(), (v->array_range()).end());
+                return *v;
+            }
+        };
+
+        class sort_by_function : public function_base
+        {
+        public:
+            sort_by_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_value() && args[1].is_expression()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                if (arg0.size() <= 1)
+                {
+                    return arg0;
+                }
+
+                const auto& expr = args[1].expression();
+
+                auto v = resources.create_json(arg0);
+                std::stable_sort((v->array_range()).begin(), (v->array_range()).end(),
+                    [&expr,&resources,&ec](reference lhs, reference rhs) -> bool
+                {
+                    std::error_code ec2;
+                    reference key1 = expr.evaluate(lhs, resources, ec2);
+                    bool is_number = key1.is_number();
+                    bool is_string = key1.is_string();
+                    if (!(is_number || is_string))
+                    {
+                        ec = jmespath_errc::invalid_type;
+                    }
+
+                    reference key2 = expr.evaluate(rhs, resources, ec2);
+                    if (!(key2.is_number() == is_number && key2.is_string() == is_string))
+                    {
+                        ec = jmespath_errc::invalid_type;
+                    }
+                    
+                    return key1 < key2;
+                });
+                return ec ? resources.null_value() : *v;
+            }
+
+            std::string to_string(std::size_t = 0) const override
+            {
+                return std::string("sort_by_function\n");
+            }
+        };
+
+        class keys_function final : public function_base
+        {
+        public:
+            keys_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_object())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+                result->reserve(args.size());
+
+                for (auto& item : arg0.object_range())
+                {
+                    result->emplace_back(item.key());
+                }
+                return *result;
+            }
+        };
+
+        class values_function final : public function_base
+        {
+        public:
+            values_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_object())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+                result->reserve(args.size());
+
+                for (auto& item : arg0.object_range())
+                {
+                    result->emplace_back(item.value());
+                }
+                return *result;
+            }
+        };
+
+        class reverse_function final : public function_base
+        {
+        public:
+            reverse_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                switch (arg0.type())
+                {
+                    case json_type::string_value:
+                    {
+                        string_view_type sv = arg0.as_string_view();
+                        std::basic_string<char32_t> buf;
+                        unicode_traits::convert(sv.data(), sv.size(), buf);
+                        std::reverse(buf.begin(), buf.end());
+                        string_type s;
+                        unicode_traits::convert(buf.data(), buf.size(), s);
+                        return *resources.create_json(s);
+                    }
+                    case json_type::array_value:
+                    {
+                        auto result = resources.create_json(arg0);
+                        std::reverse(result->array_range().begin(),result->array_range().end());
+                        return *result;
+                    }
+                    default:
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                }
+            }
+        };
+
+        class starts_with_function : public function_base
+        {
+        public:
+            starts_with_function()
+                : function_base(2)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!(args[0].is_value() && args[1].is_value()))
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_string())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg1 = args[1].value();
+                if (!arg1.is_string())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                auto sv0 = arg0.template as<string_view_type>();
+                auto sv1 = arg1.template as<string_view_type>();
+
+                if (sv1.length() <= sv0.length() && sv1 == sv0.substr(0, sv1.length()))
+                {
+                    return resources.true_value();
+                }
+                else
+                {
+                    return resources.false_value();
+                }
+            }
+        };
+
+        class sum_function : public function_base
+        {
+        public:
+            sum_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (!arg0.is_array())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+                double sum = 0;
+                for (auto& j : arg0.array_range())
+                {
+                    if (!j.is_number())
+                    {
+                        ec = jmespath_errc::invalid_type;
+                        return resources.null_value();
+                    }
+                    sum += j.template as<double>();
+                }
+
+                return *resources.create_json(sum);
+            }
+        };
+
+        class to_array_function final : public function_base
+        {
+        public:
+            to_array_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                if (arg0.is_array())
+                {
+                    return arg0;
+                }
+                else
+                {
+                    auto result = resources.create_json(json_array_arg);
+                    result->push_back(arg0);
+                    return *result;
+                }
+            }
+
+            std::string to_string(std::size_t = 0) const override
+            {
+                return std::string("to_array_function\n");
+            }
+        };
+
+        class to_number_function final : public function_base
+        {
+        public:
+            to_number_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                switch (arg0.type())
+                {
+                    case json_type::int64_value:
+                    case json_type::uint64_value:
+                    case json_type::double_value:
+                        return arg0;
+                    case json_type::string_value:
+                    {
+                        auto sv = arg0.as_string_view();
+                        uint64_t uval{ 0 };
+                        auto result1 = jsoncons::detail::to_integer(sv.data(), sv.length(), uval);
+                        if (result1)
+                        {
+                            return *resources.create_json(uval);
+                        }
+                        int64_t sval{ 0 };
+                        auto result2 = jsoncons::detail::to_integer(sv.data(), sv.length(), sval);
+                        if (result2)
+                        {
+                            return *resources.create_json(sval);
+                        }
+                        jsoncons::detail::chars_to to_double;
+                        try
+                        {
+                            auto s = arg0.as_string();
+                            double d = to_double(s.c_str(), s.length());
+                            return *resources.create_json(d);
+                        }
+                        catch (const std::exception&)
+                        {
+                            return resources.null_value();
+                        }
+                    }
+                    default:
+                        return resources.null_value();
+                }
+            }
+
+            std::string to_string(std::size_t = 0) const override
+            {
+                return std::string("to_number_function\n");
+            }
+        };
+
+        class to_string_function final : public function_base
+        {
+        public:
+            to_string_function()
+                : function_base(1)
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                JSONCONS_ASSERT(args.size() == *this->arity());
+
+                if (!args[0].is_value())
+                {
+                    ec = jmespath_errc::invalid_type;
+                    return resources.null_value();
+                }
+
+                reference arg0 = args[0].value();
+                return *resources.create_json(arg0.template as<string_type>());
+            }
+
+            std::string to_string(std::size_t = 0) const override
+            {
+                return std::string("to_string_function\n");
+            }
+        };
+
+        class not_null_function final : public function_base
+        {
+        public:
+            not_null_function()
+                : function_base(jsoncons::optional<std::size_t>())
+            {
+            }
+
+            reference evaluate(std::vector<parameter>& args, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                for (auto& param : args)
+                {
+                    if (param.is_value() && !param.value().is_null())
+                    {
+                        return param.value();
+                    }
+                }
+                return resources.null_value();
+            }
+
+            std::string to_string(std::size_t = 0) const override
+            {
+                return std::string("to_string_function\n");
+            }
+        };
+
+        // token
+
+        class token
+        {
+        public:
+            token_kind type_;
+
+            union
+            {
+                std::unique_ptr<expression_base> expression_;
+                const unary_operator* unary_operator_;
+                const binary_operator* binary_operator_;
+                const function_base* function_;
+                Json value_;
+                string_type key_;
+            };
+        public:
+
+            token(current_node_arg_t) noexcept
+                : type_(token_kind::current_node)
+            {
+            }
+
+            token(end_function_arg_t) noexcept
+                : type_(token_kind::end_function)
+            {
+            }
+
+            token(separator_arg_t) noexcept
+                : type_(token_kind::separator)
+            {
+            }
+
+            token(lparen_arg_t) noexcept
+                : type_(token_kind::lparen)
+            {
+            }
+
+            token(rparen_arg_t) noexcept
+                : type_(token_kind::rparen)
+            {
+            }
+
+            token(end_of_expression_arg_t) noexcept
+                : type_(token_kind::end_of_expression)
+            {
+            }
+
+            token(begin_multi_select_hash_arg_t) noexcept
+                : type_(token_kind::begin_multi_select_hash)
+            {
+            }
+
+            token(end_multi_select_hash_arg_t) noexcept
+                : type_(token_kind::end_multi_select_hash)
+            {
+            }
+
+            token(begin_multi_select_list_arg_t) noexcept
+                : type_(token_kind::begin_multi_select_list)
+            {
+            }
+
+            token(end_multi_select_list_arg_t) noexcept
+                : type_(token_kind::end_multi_select_list)
+            {
+            }
+
+            token(begin_filter_arg_t) noexcept
+                : type_(token_kind::begin_filter)
+            {
+            }
+
+            token(end_filter_arg_t) noexcept
+                : type_(token_kind::end_filter)
+            {
+            }
+
+            token(pipe_arg_t) noexcept
+                : type_(token_kind::pipe)
+            {
+            }
+
+            token(key_arg_t, const string_type& key)
+                : type_(token_kind::key)
+            {
+                new (&key_) string_type(key);
+            }
+
+            token(std::unique_ptr<expression_base>&& expression)
+                : type_(token_kind::expression)
+            {
+                new (&expression_) std::unique_ptr<expression_base>(std::move(expression));
+            }
+
+            token(const unary_operator* expression) noexcept
+                : type_(token_kind::unary_operator),
+                  unary_operator_(expression)
+            {
+            }
+
+            token(const binary_operator* expression) noexcept
+                : type_(token_kind::binary_operator),
+                  binary_operator_(expression)
+            {
+            }
+
+            token(const function_base* function) noexcept
+                : type_(token_kind::function),
+                  function_(function)
+            {
+            }
+
+            token(argument_arg_t) noexcept
+                : type_(token_kind::argument)
+            {
+            }
+
+            token(begin_expression_type_arg_t) noexcept
+                : type_(token_kind::begin_expression_type)
+            {
+            }
+
+            token(end_expression_type_arg_t) noexcept
+                : type_(token_kind::end_expression_type)
+            {
+            }
+
+            token(literal_arg_t, Json&& value) noexcept
+                : type_(token_kind::literal), value_(std::move(value))
+            {
+            }
+
+            token(token&& other) noexcept
+            {
+                construct(std::forward<token>(other));
+            }
+
+            token& operator=(token&& other)
+            {
+                if (&other != this)
+                {
+                    if (type_ == other.type_)
+                    {
+                        switch (type_)
+                        {
+                            case token_kind::expression:
+                                expression_ = std::move(other.expression_);
+                                break;
+                            case token_kind::key:
+                                key_ = std::move(other.key_);
+                                break;
+                            case token_kind::unary_operator:
+                                unary_operator_ = other.unary_operator_;
+                                break;
+                            case token_kind::binary_operator:
+                                binary_operator_ = other.binary_operator_;
+                                break;
+                            case token_kind::function:
+                                function_ = other.function_;
+                                break;
+                            case token_kind::literal:
+                                value_ = std::move(other.value_);
+                                break;
+                            default:
+                                break;
+                        }
+                    }
+                    else
+                    {
+                        destroy();
+                        construct(std::forward<token>(other));
+                    }
+                }
+                return *this;
+            }
+
+            ~token() noexcept
+            {
+                destroy();
+            }
+
+            token_kind type() const
+            {
+                return type_;
+            }
+
+            bool is_lparen() const
+            {
+                return type_ == token_kind::lparen; 
+            }
+
+            bool is_lbrace() const
+            {
+                return type_ == token_kind::begin_multi_select_hash; 
+            }
+
+            bool is_key() const
+            {
+                return type_ == token_kind::key; 
+            }
+
+            bool is_rparen() const
+            {
+                return type_ == token_kind::rparen; 
+            }
+
+            bool is_current_node() const
+            {
+                return type_ == token_kind::current_node; 
+            }
+
+            bool is_projection() const
+            {
+                return type_ == token_kind::expression && expression_->is_projection(); 
+            }
+
+            bool is_expression() const
+            {
+                return type_ == token_kind::expression; 
+            }
+
+            bool is_operator() const
+            {
+                return type_ == token_kind::unary_operator || 
+                       type_ == token_kind::binary_operator; 
+            }
+
+            std::size_t precedence_level() const
+            {
+                switch(type_)
+                {
+                    case token_kind::unary_operator:
+                        return unary_operator_->precedence_level();
+                    case token_kind::binary_operator:
+                        return binary_operator_->precedence_level();
+                    case token_kind::expression:
+                        return expression_->precedence_level();
+                    default:
+                        return 0;
+                }
+            }
+
+            jsoncons::optional<std::size_t> arity() const
+            {
+                return type_ == token_kind::function ? function_->arity() : jsoncons::optional<std::size_t>();
+            }
+
+            bool is_right_associative() const
+            {
+                switch(type_)
+                {
+                    case token_kind::unary_operator:
+                        return unary_operator_->is_right_associative();
+                    case token_kind::binary_operator:
+                        return binary_operator_->is_right_associative();
+                    case token_kind::expression:
+                        return expression_->is_right_associative();
+                    default:
+                        return false;
+                }
+            }
+
+            void construct(token&& other)
+            {
+                type_ = other.type_;
+                switch (type_)
+                {
+                    case token_kind::expression:
+                        new (&expression_) std::unique_ptr<expression_base>(std::move(other.expression_));
+                        break;
+                    case token_kind::key:
+                        new (&key_) string_type(std::move(other.key_));
+                        break;
+                    case token_kind::unary_operator:
+                        unary_operator_ = other.unary_operator_;
+                        break;
+                    case token_kind::binary_operator:
+                        binary_operator_ = other.binary_operator_;
+                        break;
+                    case token_kind::function:
+                        function_ = other.function_;
+                        break;
+                    case token_kind::literal:
+                        new (&value_) Json(std::move(other.value_));
+                        break;
+                    default:
+                        break;
+                }
+            }
+
+            void destroy() noexcept 
+            {
+                switch(type_)
+                {
+                    case token_kind::expression:
+                        expression_.~unique_ptr();
+                        break;
+                    case token_kind::key:
+                        key_.~basic_string();
+                        break;
+                    case token_kind::literal:
+                        value_.~Json();
+                        break;
+                    default:
+                        break;
+                }
+            }
+
+            std::string to_string(std::size_t indent = 0) const
+            {
+                switch(type_)
+                {
+                    case token_kind::expression:
+                        return expression_->to_string(indent);
+                        break;
+                    case token_kind::unary_operator:
+                        return std::string("unary_operator");
+                        break;
+                    case token_kind::binary_operator:
+                        return binary_operator_->to_string(indent);
+                        break;
+                    case token_kind::current_node:
+                        return std::string("current_node");
+                        break;
+                    case token_kind::end_function:
+                        return std::string("end_function");
+                        break;
+                    case token_kind::separator:
+                        return std::string("separator");
+                        break;
+                    case token_kind::literal:
+                        return std::string("literal");
+                        break;
+                    case token_kind::key:
+                        return std::string("key") + key_;
+                        break;
+                    case token_kind::begin_multi_select_hash:
+                        return std::string("begin_multi_select_hash");
+                        break;
+                    case token_kind::begin_multi_select_list:
+                        return std::string("begin_multi_select_list");
+                        break;
+                    case token_kind::begin_filter:
+                        return std::string("begin_filter");
+                        break;
+                    case token_kind::pipe:
+                        return std::string("pipe");
+                        break;
+                    case token_kind::lparen:
+                        return std::string("lparen");
+                        break;
+                    case token_kind::function:
+                        return function_->to_string();
+                    case token_kind::argument:
+                        return std::string("argument");
+                        break;
+                    case token_kind::begin_expression_type:
+                        return std::string("begin_expression_type");
+                        break;
+                    case token_kind::end_expression_type:
+                        return std::string("end_expression_type");
+                        break;
+                    default:
+                        return std::string("default");
+                        break;
+                }
+            }
+        };
+
+        static pointer evaluate_tokens(reference doc, const std::vector<token>& output_stack, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec)
+        {
+            pointer root_ptr = std::addressof(doc);
+            std::vector<parameter> stack;
+            std::vector<parameter> arg_stack;
+            for (std::size_t i = 0; i < output_stack.size(); ++i)
+            {
+                auto& t = output_stack[i];
+                switch (t.type())
+                {
+                    case token_kind::literal:
+                    {
+                        stack.emplace_back(t.value_);
+                        break;
+                    }
+                    case token_kind::begin_expression_type:
+                    {
+                        JSONCONS_ASSERT(i+1 < output_stack.size());
+                        ++i;
+                        JSONCONS_ASSERT(output_stack[i].is_expression());
+                        JSONCONS_ASSERT(!stack.empty());
+                        stack.pop_back();
+                        stack.emplace_back(output_stack[i].expression_.get());
+                        break;
+                    }
+                    case token_kind::pipe:
+                    {
+                        JSONCONS_ASSERT(!stack.empty());
+                        root_ptr = std::addressof(stack.back().value());
+                        break;
+                    }
+                    case token_kind::current_node:
+                        stack.emplace_back(*root_ptr);
+                        break;
+                    case token_kind::expression:
+                    {
+                        JSONCONS_ASSERT(!stack.empty());
+                        pointer ptr = std::addressof(stack.back().value());
+                        stack.pop_back();
+                        auto& ref = t.expression_->evaluate(*ptr, resources, ec);
+                        stack.emplace_back(ref);
+                        break;
+                    }
+                    case token_kind::unary_operator:
+                    {
+                        JSONCONS_ASSERT(stack.size() >= 1);
+                        pointer ptr = std::addressof(stack.back().value());
+                        stack.pop_back();
+                        reference r = t.unary_operator_->evaluate(*ptr, resources, ec);
+                        stack.emplace_back(r);
+                        break;
+                    }
+                    case token_kind::binary_operator:
+                    {
+                        JSONCONS_ASSERT(stack.size() >= 2);
+                        pointer rhs = std::addressof(stack.back().value());
+                        stack.pop_back();
+                        pointer lhs = std::addressof(stack.back().value());
+                        stack.pop_back();
+                        reference r = t.binary_operator_->evaluate(*lhs,*rhs, resources, ec);
+                        stack.emplace_back(r);
+                        break;
+                    }
+                    case token_kind::argument:
+                    {
+                        JSONCONS_ASSERT(!stack.empty());
+                        arg_stack.push_back(std::move(stack.back()));
+                        stack.pop_back();
+                        break;
+                    }
+                    case token_kind::function:
+                    {
+                        if (t.function_->arity() && *(t.function_->arity()) != arg_stack.size())
+                        {
+                            ec = jmespath_errc::invalid_arity;
+                            return std::addressof(resources.null_value());
+                        }
+
+                        reference r = t.function_->evaluate(arg_stack, resources, ec);
+                        if (ec)
+                        {
+                            return std::addressof(resources.null_value());
+                        }
+                        arg_stack.clear();
+                        stack.emplace_back(r);
+                        break;
+                    }
+                    default:
+                        break;
+                }
+            }
+            JSONCONS_ASSERT(stack.size() == 1);
+            return std::addressof(stack.back().value());
+        }
+
+        // Implementations
+
+        class or_operator final : public binary_operator
+        {
+        public:
+            or_operator()
+                : binary_operator(operator_kind::or_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                if (lhs.is_null() && rhs.is_null())
+                {
+                    return resources.null_value();
+                }
+                if (!is_false(lhs))
+                {
+                    return lhs;
+                }
+                else
+                {
+                    return rhs;
+                }
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("or_operator\n");
+                return s;
+            }
+        };
+
+        class and_operator final : public binary_operator
+        {
+        public:
+            and_operator()
+                : binary_operator(operator_kind::and_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>&, std::error_code&) const override
+            {
+                if (is_true(lhs))
+                {
+                    return rhs;
+                }
+                else
+                {
+                    return lhs;
+                }
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("and_operator\n");
+                return s;
+            }
+        };
+
+        class eq_operator final : public binary_operator
+        {
+        public:
+            eq_operator()
+                : binary_operator(operator_kind::eq_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override 
+            {
+                return lhs == rhs ? resources.true_value() : resources.false_value();
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("eq_operator\n");
+                return s;
+            }
+        };
+
+        class ne_operator final : public binary_operator
+        {
+        public:
+            ne_operator()
+                : binary_operator(operator_kind::ne_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override 
+            {
+                return lhs != rhs ? resources.true_value() : resources.false_value();
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("ne_operator\n");
+                return s;
+            }
+        };
+
+        class lt_operator final : public binary_operator
+        {
+        public:
+            lt_operator()
+                : binary_operator(operator_kind::lt_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override 
+            {
+                if (!(lhs.is_number() && rhs.is_number()))
+                {
+                    return resources.null_value();
+                }
+                return lhs < rhs ? resources.true_value() : resources.false_value();
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("lt_operator\n");
+                return s;
+            }
+        };
+
+        class lte_operator final : public binary_operator
+        {
+        public:
+            lte_operator()
+                : binary_operator(operator_kind::lte_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override 
+            {
+                if (!(lhs.is_number() && rhs.is_number()))
+                {
+                    return resources.null_value();
+                }
+                return lhs <= rhs ? resources.true_value() : resources.false_value();
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("lte_operator\n");
+                return s;
+            }
+        };
+
+        class gt_operator final : public binary_operator
+        {
+        public:
+            gt_operator()
+                : binary_operator(operator_kind::gt_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                if (!(lhs.is_number() && rhs.is_number()))
+                {
+                    return resources.null_value();
+                }
+                return lhs > rhs ? resources.true_value() : resources.false_value();
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("gt_operator\n");
+                return s;
+            }
+        };
+
+        class gte_operator final : public binary_operator
+        {
+        public:
+            gte_operator()
+                : binary_operator(operator_kind::gte_op)
+            {
+            }
+
+            reference evaluate(reference lhs, reference rhs, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                if (!(lhs.is_number() && rhs.is_number()))
+                {
+                    return resources.null_value();
+                }
+                return lhs >= rhs ? resources.true_value() : resources.false_value();
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("gte_operator\n");
+                return s;
+            }
+        };
+
+        // basic_expression
+        class basic_expression :  public expression_base
+        {
+        public:
+            basic_expression()
+                : expression_base(operator_kind::default_op, false)
+            {
+            }
+
+            void add_expression(std::unique_ptr<expression_base>&&) override
+            {
+            }
+        };
+
+        class identifier_selector final : public basic_expression
+        {
+        private:
+            string_type identifier_;
+        public:
+            identifier_selector(const string_view_type& name)
+                : identifier_(name)
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                //std::cout << "(identifier_selector " << identifier_  << " ) " << pretty_print(val) << "\n";
+                if (val.is_object() && val.contains(identifier_))
+                {
+                    return val.at(identifier_);
+                }
+                else 
+                {
+                    return resources.null_value();
+                }
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("identifier_selector ");
+                s.append(identifier_);
+                return s;
+            }
+        };
+
+        class current_node final : public basic_expression
+        {
+        public:
+            current_node()
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>&, std::error_code&) const override
+            {
+                return val;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("current_node ");
+                return s;
+            }
+        };
+
+        class index_selector final : public basic_expression
+        {
+            int64_t index_;
+        public:
+            index_selector(int64_t index)
+                : index_(index)
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code&) const override
+            {
+                if (!val.is_array())
+                {
+                    return resources.null_value();
+                }
+                int64_t slen = static_cast<int64_t>(val.size());
+                if (index_ >= 0 && index_ < slen)
+                {
+                    std::size_t index = static_cast<std::size_t>(index_);
+                    return val.at(index);
+                }
+                else if ((slen + index_) >= 0 && (slen+index_) < slen)
+                {
+                    std::size_t index = static_cast<std::size_t>(slen + index_);
+                    return val.at(index);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("index_selector ");
+                s.append(std::to_string(index_));
+                return s;
+            }
+        };
+
+        // projection_base
+        class projection_base : public expression_base
+        {
+        protected:
+            std::vector<std::unique_ptr<expression_base>> expressions_;
+        public:
+            projection_base(operator_kind oper)
+                : expression_base(oper, true)
+            {
+            }
+
+            void add_expression(std::unique_ptr<expression_base>&& expr) override
+            {
+                if (!expressions_.empty() && expressions_.back()->is_projection() && 
+                    (expr->precedence_level() < expressions_.back()->precedence_level() ||
+                     (expr->precedence_level() == expressions_.back()->precedence_level() && expr->is_right_associative())))
+                {
+                    expressions_.back()->add_expression(std::move(expr));
+                }
+                else
+                {
+                    expressions_.emplace_back(std::move(expr));
+                }
+            }
+
+            reference apply_expressions(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const
+            {
+                pointer ptr = std::addressof(val);
+                for (auto& expression : expressions_)
+                {
+                    ptr = std::addressof(expression->evaluate(*ptr, resources, ec));
+                }
+                return *ptr;
+            }
+        };
+
+        class object_projection final : public projection_base
+        {
+        public:
+            object_projection()
+                : projection_base(operator_kind::projection_op)
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (!val.is_object())
+                {
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+                for (auto& item : val.object_range())
+                {
+                    if (!item.value().is_null())
+                    {
+                        reference j = this->apply_expressions(item.value(), resources, ec);
+                        if (!j.is_null())
+                        {
+                            result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                        }
+                    }
+                }
+                return *result;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("object_projection\n");
+                for (auto& expr : this->expressions_)
+                {
+                    std::string sss = expr->to_string(indent+2);
+                    s.insert(s.end(), sss.begin(), sss.end());
+                    s.push_back('\n');
+                }
+                return s;
+            }
+        };
+
+        class list_projection final : public projection_base
+        {
+        public:
+            list_projection()
+                : projection_base(operator_kind::projection_op)
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (!val.is_array())
+                {
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+                for (reference item : val.array_range())
+                {
+                    if (!item.is_null())
+                    {
+                        reference j = this->apply_expressions(item, resources, ec);
+                        if (!j.is_null())
+                        {
+                            result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                        }
+                    }
+                }
+                return *result;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("list_projection\n");
+                for (auto& expr : this->expressions_)
+                {
+                    std::string sss = expr->to_string(indent+2);
+                    s.insert(s.end(), sss.begin(), sss.end());
+                    s.push_back('\n');
+                }
+                return s;
+            }
+        };
+
+        class slice_projection final : public projection_base
+        {
+            slice slice_;
+        public:
+            slice_projection(const slice& s)
+                : projection_base(operator_kind::projection_op), slice_(s)
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (!val.is_array())
+                {
+                    return resources.null_value();
+                }
+
+                auto start = slice_.get_start(val.size());
+                auto end = slice_.get_stop(val.size());
+                auto step = slice_.step();
+
+                if (step == 0)
+                {
+                    ec = jmespath_errc::step_cannot_be_zero;
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+                if (step > 0)
+                {
+                    if (start < 0)
+                    {
+                        start = 0;
+                    }
+                    if (end > static_cast<int64_t>(val.size()))
+                    {
+                        end = val.size();
+                    }
+                    for (int64_t i = start; i < end; i += step)
+                    {
+                        reference j = this->apply_expressions(val.at(static_cast<std::size_t>(i)), resources, ec);
+                        if (!j.is_null())
+                        {
+                            result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                        }
+                    }
+                }
+                else
+                {
+                    if (start >= static_cast<int64_t>(val.size()))
+                    {
+                        start = static_cast<int64_t>(val.size()) - 1;
+                    }
+                    if (end < -1)
+                    {
+                        end = -1;
+                    }
+                    for (int64_t i = start; i > end; i += step)
+                    {
+                        reference j = this->apply_expressions(val.at(static_cast<std::size_t>(i)), resources, ec);
+                        if (!j.is_null())
+                        {
+                            result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                        }
+                    }
+                }
+
+                return *result;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("slice_projection\n");
+                for (auto& expr : this->expressions_)
+                {
+                    std::string sss = expr->to_string(indent+2);
+                    s.insert(s.end(), sss.begin(), sss.end());
+                    s.push_back('\n');
+                }
+                return s;
+            }
+        };
+
+        class filter_expression final : public projection_base
+        {
+            std::vector<token> token_list_;
+        public:
+            filter_expression(std::vector<token>&& token_list)
+                : projection_base(operator_kind::projection_op), token_list_(std::move(token_list))
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (!val.is_array())
+                {
+                    return resources.null_value();
+                }
+                auto result = resources.create_json(json_array_arg);
+
+                for (auto& item : val.array_range())
+                {
+                    Json j(json_const_pointer_arg, evaluate_tokens(item, token_list_, resources, ec));
+                    if (is_true(j))
+                    {
+                        reference jj = this->apply_expressions(item, resources, ec);
+                        if (!jj.is_null())
+                        {
+                            result->emplace_back(json_const_pointer_arg, std::addressof(jj));
+                        }
+                    }
+                }
+                return *result;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("filter_expression\n");
+                for (auto& item : token_list_)
+                {
+                    std::string sss = item.to_string(indent+2);
+                    s.insert(s.end(), sss.begin(), sss.end());
+                    s.push_back('\n');
+                }
+                return s;
+            }
+        };
+
+        class flatten_projection final : public projection_base
+        {
+        public:
+            flatten_projection()
+                : projection_base(operator_kind::flatten_projection_op)
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (!val.is_array())
+                {
+                    return resources.null_value();
+                }
+
+                auto result = resources.create_json(json_array_arg);
+                for (reference current_elem : val.array_range())
+                {
+                    if (current_elem.is_array())
+                    {
+                        for (reference elem : current_elem.array_range())
+                        {
+                            if (!elem.is_null())
+                            {
+                                reference j = this->apply_expressions(elem, resources, ec);
+                                if (!j.is_null())
+                                {
+                                    result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                                }
+                            }
+                        }
+                    }
+                    else
+                    {
+                        if (!current_elem.is_null())
+                        {
+                            reference j = this->apply_expressions(current_elem, resources, ec);
+                            if (!j.is_null())
+                            {
+                                result->emplace_back(json_const_pointer_arg, std::addressof(j));
+                            }
+                        }
+                    }
+                }
+                return *result;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("flatten_projection\n");
+                for (auto& expr : this->expressions_)
+                {
+                    std::string sss = expr->to_string(indent+2);
+                    s.insert(s.end(), sss.begin(), sss.end());
+                    s.push_back('\n');
+                }
+                return s;
+            }
+        };
+
+        class multi_select_list final : public basic_expression
+        {
+            std::vector<std::vector<token>> token_lists_;
+        public:
+            multi_select_list(std::vector<std::vector<token>>&& token_lists)
+                : token_lists_(std::move(token_lists))
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (val.is_null())
+                {
+                    return val;
+                }
+                auto result = resources.create_json(json_array_arg);
+                result->reserve(token_lists_.size());
+
+                for (auto& list : token_lists_)
+                {
+                    result->emplace_back(json_const_pointer_arg, evaluate_tokens(val, list, resources, ec));
+                }
+                return *result;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("multi_select_list\n");
+                for (auto& list : token_lists_)
+                {
+                    for (auto& item : list)
+                    {
+                        std::string sss = item.to_string(indent+2);
+                        s.insert(s.end(), sss.begin(), sss.end());
+                        s.push_back('\n');
+                    }
+                    s.append("---\n");
+                }
+                return s;
+            }
+        };
+
+        struct key_tokens
+        {
+            string_type key;
+            std::vector<token> tokens;
+
+            key_tokens(string_type&& key, std::vector<token>&& tokens) noexcept
+                : key(std::move(key)), tokens(std::move(tokens))
+            {
+            }
+        };
+
+        class multi_select_hash final : public basic_expression
+        {
+        public:
+            std::vector<key_tokens> key_toks_;
+
+            multi_select_hash(std::vector<key_tokens>&& key_toks)
+                : key_toks_(std::move(key_toks))
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                if (val.is_null())
+                {
+                    return val;
+                }
+                auto resultp = resources.create_json(json_object_arg);
+                resultp->reserve(key_toks_.size());
+                for (auto& item : key_toks_)
+                {
+                    resultp->try_emplace(item.key, json_const_pointer_arg, evaluate_tokens(val, item.tokens, resources, ec));
+                }
+
+                return *resultp;
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("multi_select_list\n");
+                return s;
+            }
+        };
+
+        class function_expression final : public basic_expression
+        {
+        public:
+            std::vector<token> toks_;
+
+            function_expression(std::vector<token>&& toks)
+                : toks_(std::move(toks))
+            {
+            }
+
+            reference evaluate(reference val, dynamic_resources<Json,JsonReference>& resources, std::error_code& ec) const override
+            {
+                return *evaluate_tokens(val, toks_, resources, ec);
+            }
+
+            std::string to_string(std::size_t indent = 0) const override
+            {
+                std::string s;
+                for (std::size_t i = 0; i <= indent; ++i)
+                {
+                    s.push_back(' ');
+                }
+                s.append("function_expression\n");
+                for (auto& tok : toks_)
+                {
+                    for (std::size_t i = 0; i <= indent+2; ++i)
+                    {
+                        s.push_back(' ');
+                    }
+                    std::string sss = tok.to_string(indent+2);
+                    s.insert(s.end(), sss.begin(), sss.end());
+                    s.push_back('\n');
+                }
+                return s;
+            }
+        };
+
+        class static_resources
+        {
+            std::vector<std::unique_ptr<Json>> temp_storage_;
+
+        public:
+
+            static_resources() = default;
+            static_resources(const static_resources& expr) = delete;
+            static_resources& operator=(const static_resources& expr) = delete;
+            static_resources(static_resources&& expr) = default;
+            static_resources& operator=(static_resources&& expr) = default;
+
+            const function_base* get_function(const string_type& name, std::error_code& ec) const
+            {
+                static abs_function abs_func;
+                static avg_function avg_func;
+                static ceil_function ceil_func;
+                static contains_function contains_func;
+                static ends_with_function ends_with_func;
+                static floor_function floor_func;
+                static join_function join_func;
+                static length_function length_func;
+                static max_function max_func;
+                static max_by_function max_by_func;
+                static map_function map_func;
+                static merge_function merge_func;
+                static min_function min_func;
+                static min_by_function min_by_func;
+                static type_function type_func;
+                static sort_function sort_func;
+                static sort_by_function sort_by_func;
+                static keys_function keys_func;
+                static values_function values_func;
+                static reverse_function reverse_func;
+                static starts_with_function starts_with_func;
+                static const sum_function sum_func;
+                static to_array_function to_array_func;
+                static to_number_function to_number_func;
+                static to_string_function to_string_func;
+                static not_null_function not_null_func;
+
+                using function_dictionary = std::unordered_map<string_type,const function_base*>;
+                static const function_dictionary functions_ =
+                {
+                    {string_type{'a','b','s'}, &abs_func},
+                    {string_type{'a','v','g'}, &avg_func},
+                    {string_type{'c','e','i', 'l'}, &ceil_func},
+                    {string_type{'c','o','n', 't', 'a', 'i', 'n', 's'}, &contains_func},
+                    {string_type{'e','n','d', 's', '_', 'w', 'i', 't', 'h'}, &ends_with_func},
+                    {string_type{'f','l','o', 'o', 'r'}, &floor_func},
+                    {string_type{'j','o','i', 'n'}, &join_func},
+                    {string_type{'l','e','n', 'g', 't', 'h'}, &length_func},
+                    {string_type{'m','a','x'}, &max_func},
+                    {string_type{'m','a','x','_','b','y'}, &max_by_func},
+                    {string_type{'m','a','p'}, &map_func},
+                    {string_type{'m','i','n'}, &min_func},
+                    {string_type{'m','i','n','_','b','y'}, &min_by_func},
+                    {string_type{'m','e','r', 'g', 'e'}, &merge_func},
+                    {string_type{'t','y','p', 'e'}, &type_func},
+                    {string_type{'s','o','r', 't'}, &sort_func},
+                    {string_type{'s','o','r', 't','_','b','y'}, &sort_by_func},
+                    {string_type{'k','e','y', 's'}, &keys_func},
+                    {string_type{'v','a','l', 'u','e','s'}, &values_func},
+                    {string_type{'r','e','v', 'e', 'r', 's','e'}, &reverse_func},
+                    {string_type{'s','t','a', 'r','t','s','_','w','i','t','h'}, &starts_with_func},
+                    {string_type{'s','u','m'}, &sum_func},
+                    {string_type{'t','o','_','a','r','r','a','y',}, &to_array_func},
+                    {string_type{'t','o','_', 'n', 'u', 'm','b','e','r'}, &to_number_func},
+                    {string_type{'t','o','_', 's', 't', 'r','i','n','g'}, &to_string_func},
+                    {string_type{'n','o','t', '_', 'n', 'u','l','l'}, &not_null_func}
+                };
+                auto it = functions_.find(name);
+                if (it == functions_.end())
+                {
+                    ec = jmespath_errc::unknown_function;
+                    return nullptr;
+                }
+                return it->second;
+            }
+
+            const unary_operator* get_not_operator() const
+            {
+                static const not_expression not_oper;
+
+                return &not_oper;
+            }
+
+            const binary_operator* get_or_operator() const
+            {
+                static const or_operator or_oper;
+
+                return &or_oper;
+            }
+
+            const binary_operator* get_and_operator() const
+            {
+                static const and_operator and_oper;
+
+                return &and_oper;
+            }
+
+            const binary_operator* get_eq_operator() const
+            {
+                static const eq_operator eq_oper;
+                return &eq_oper;
+            }
+
+            const binary_operator* get_ne_operator() const
+            {
+                static const ne_operator ne_oper;
+                return &ne_oper;
+            }
+
+            const binary_operator* get_lt_operator() const
+            {
+                static const lt_operator lt_oper;
+                return &lt_oper;
+            }
+
+            const binary_operator* get_lte_operator() const
+            {
+                static const lte_operator lte_oper;
+                return &lte_oper;
+            }
+
+            const binary_operator* get_gt_operator() const
+            {
+                static const gt_operator gt_oper;
+                return &gt_oper;
+            }
+
+            const binary_operator* get_gte_operator() const
+            {
+                static const gte_operator gte_oper;
+                return &gte_oper;
+            }
+        };
+
+        class jmespath_expression
+        {
+            static_resources resources_;
+            std::vector<token> output_stack_;
+        public:
+            jmespath_expression()
+            {
+            }
+
+            jmespath_expression(const jmespath_expression& expr) = delete;
+            jmespath_expression& operator=(const jmespath_expression& expr) = delete;
+
+            jmespath_expression(jmespath_expression&& expr)
+                : resources_(std::move(expr.resources_)),
+                  output_stack_(std::move(expr.output_stack_))
+            {
+            }
+
+            jmespath_expression(static_resources&& resources,
+                                std::vector<token>&& output_stack)
+                : resources_(std::move(resources)), output_stack_(std::move(output_stack))
+            {
+            }
+
+            Json evaluate(reference doc)
+            {
+                if (output_stack_.empty())
+                {
+                    return Json::null();
+                }
+                std::error_code ec;
+                Json result = evaluate(doc, ec);
+                if (ec)
+                {
+                    JSONCONS_THROW(jmespath_error(ec));
+                }
+                return result;
+            }
+
+            Json evaluate(reference doc, std::error_code& ec)
+            {
+                if (output_stack_.empty())
+                {
+                    return Json::null();
+                }
+                dynamic_resources<Json,JsonReference> dynamic_storage;
+                return deep_copy(*evaluate_tokens(doc, output_stack_, dynamic_storage, ec));
+            }
+
+            static jmespath_expression compile(const string_view_type& expr)
+            {
+                jsoncons::jmespath::detail::jmespath_evaluator<Json,const Json&> evaluator;
+                std::error_code ec;
+                jmespath_expression result = evaluator.compile(expr.data(), expr.size(), ec);
+                if (ec)
+                {
+                    JSONCONS_THROW(jmespath_error(ec, evaluator.line(), evaluator.column()));
+                }
+                return result;
+            }
+
+            static jmespath_expression compile(const string_view_type& expr,
+                                               std::error_code& ec)
+            {
+                jsoncons::jmespath::detail::jmespath_evaluator<Json,const Json&> evaluator;
+                return evaluator.compile(expr.data(), expr.size(), ec);
+            }
+        };
+    private:
+        std::size_t line_;
+        std::size_t column_;
+        const char_type* begin_input_;
+        const char_type* end_input_;
+        const char_type* p_;
+
+        static_resources resources_;
+        std::vector<path_state> state_stack_;
+
+        std::vector<token> output_stack_;
+        std::vector<token> operator_stack_;
+
+    public:
+        jmespath_evaluator()
+            : line_(1), column_(1),
+              begin_input_(nullptr), end_input_(nullptr),
+              p_(nullptr)
+        {
+        }
+
+        std::size_t line() const
+        {
+            return line_;
+        }
+
+        std::size_t column() const
+        {
+            return column_;
+        }
+
+        jmespath_expression compile(const char_type* path, 
+                                    std::size_t length,
+                                    std::error_code& ec)
+        {
+            push_token(current_node_arg, ec);
+            if (ec) {return jmespath_expression();}
+            state_stack_.emplace_back(path_state::start);
+
+            string_type buffer;
+            uint32_t cp = 0;
+            uint32_t cp2 = 0;
+     
+            begin_input_ = path;
+            end_input_ = path + length;
+            p_ = begin_input_;
+
+            slice slic{};
+
+            while (p_ < end_input_)
+            {
+                switch (state_stack_.back())
+                {
+                    case path_state::start: 
+                    {
+                        state_stack_.back() = path_state::rhs_expression;
+                        state_stack_.emplace_back(path_state::lhs_expression);
+                        break;
+                    }
+                    case path_state::rhs_expression:
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '.': 
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::sub_expression);
+                                break;
+                            case '|':
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                state_stack_.emplace_back(path_state::expect_pipe_or_or);
+                                break;
+                            case '&':
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                state_stack_.emplace_back(path_state::expect_and);
+                                break;
+                            case '<':
+                            case '>':
+                            case '=':
+                            {
+                                state_stack_.emplace_back(path_state::comparator_expression);
+                                break;
+                            }
+                            case '!':
+                            {
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                state_stack_.emplace_back(path_state::cmp_ne);
+                                break;
+                            }
+                            case ')':
+                            {
+                                state_stack_.pop_back();
+                                break;
+                            }
+                            case '[':
+                                state_stack_.emplace_back(path_state::bracket_specifier);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                if (state_stack_.size() > 1)
+                                {
+                                    state_stack_.pop_back();
+                                }
+                                else
+                                {
+                                    ec = jmespath_errc::syntax_error;
+                                    return jmespath_expression();
+                                }
+                                break;
+                        }
+                        break;
+                    case path_state::comparator_expression:
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '<':
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::lhs_expression;
+                                state_stack_.emplace_back(path_state::cmp_lt_or_lte);
+                                break;
+                            case '>':
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::lhs_expression;
+                                state_stack_.emplace_back(path_state::cmp_gt_or_gte);
+                                break;
+                            case '=':
+                            {
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::lhs_expression;
+                                state_stack_.emplace_back(path_state::cmp_eq);
+                                break;
+                            }
+                            default:
+                                if (state_stack_.size() > 1)
+                                {
+                                    state_stack_.pop_back();
+                                }
+                                else
+                                {
+                                    ec = jmespath_errc::syntax_error;
+                                    return jmespath_expression();
+                                }
+                                break;
+                        }
+                        break;
+                    case path_state::lhs_expression: 
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::val_expr;
+                                state_stack_.emplace_back(path_state::quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\'':
+                                state_stack_.back() = path_state::raw_string;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '`':
+                                state_stack_.back() = path_state::literal;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '{':
+                                push_token(begin_multi_select_hash_arg, ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::multi_select_hash;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '*': // wildcard
+                                push_token(token(jsoncons::make_unique<object_projection>()), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '(':
+                            {
+                                ++p_;
+                                ++column_;
+                                push_token(lparen_arg, ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::expect_rparen;
+                                state_stack_.emplace_back(path_state::rhs_expression);
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                break;
+                            }
+                            case '!':
+                            {
+                                ++p_;
+                                ++column_;
+                                push_token(token(resources_.get_not_operator()), ec);
+                                if (ec) {return jmespath_expression();}
+                                break;
+                            }
+                            case '@':
+                                ++p_;
+                                ++column_;
+                                push_token(token(jsoncons::make_unique<current_node>()), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+                                break;
+                            case '[': 
+                                state_stack_.back() = path_state::bracket_specifier_or_multi_select_list;
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                if ((*p_ >= 'A' && *p_ <= 'Z') || (*p_ >= 'a' && *p_ <= 'z') || (*p_ == '_'))
+                                {
+                                    state_stack_.back() = path_state::identifier_or_function_expr;
+                                    state_stack_.emplace_back(path_state::unquoted_string);
+                                    buffer.push_back(*p_);
+                                    ++p_;
+                                    ++column_;
+                                }
+                                else
+                                {
+                                    ec = jmespath_errc::expected_identifier;
+                                    return jmespath_expression();
+                                }
+                                break;
+                        };
+                        break;
+                    }
+                    case path_state::sub_expression: 
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::val_expr;
+                                state_stack_.emplace_back(path_state::quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '{':
+                                push_token(begin_multi_select_hash_arg, ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::multi_select_hash;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '*':
+                                push_token(token(jsoncons::make_unique<object_projection>()), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[': 
+                                state_stack_.back() = path_state::expect_multi_select_list;
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                if ((*p_ >= 'A' && *p_ <= 'Z') || (*p_ >= 'a' && *p_ <= 'z') || (*p_ == '_'))
+                                {
+                                    state_stack_.back() = path_state::identifier_or_function_expr;
+                                    state_stack_.emplace_back(path_state::unquoted_string);
+                                    buffer.push_back(*p_);
+                                    ++p_;
+                                    ++column_;
+                                }
+                                else
+                                {
+                                    ec = jmespath_errc::expected_identifier;
+                                    return jmespath_expression();
+                                }
+                                break;
+                        };
+                        break;
+                    }
+                    case path_state::key_expr:
+                        push_token(token(key_arg, buffer), ec);
+                        if (ec) {return jmespath_expression();}
+                        buffer.clear(); 
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::val_expr:
+                        push_token(token(jsoncons::make_unique<identifier_selector>(buffer)), ec);
+                        if (ec) {return jmespath_expression();}
+                        buffer.clear();
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::expression_or_expression_type:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '&':
+                                push_token(token(begin_expression_type_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::expression_type;
+                                state_stack_.emplace_back(path_state::rhs_expression);
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.back() = path_state::argument;
+                                state_stack_.emplace_back(path_state::rhs_expression);
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                break;
+                        }
+                        break;
+                    case path_state::identifier_or_function_expr:
+                        switch(*p_)
+                        {
+                            case '(':
+                            {
+                                auto f = resources_.get_function(buffer, ec);
+                                if (ec)
+                                {
+                                    return jmespath_expression();
+                                }
+                                buffer.clear();
+                                push_token(token(f), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::function_expression;
+                                state_stack_.emplace_back(path_state::expression_or_expression_type);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                            {
+                                push_token(token(jsoncons::make_unique<identifier_selector>(buffer)), ec);
+                                if (ec) {return jmespath_expression();}
+                                buffer.clear();
+                                state_stack_.pop_back(); 
+                                break;
+                            }
+                        }
+                        break;
+
+                    case path_state::function_expression:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case ',':
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.emplace_back(path_state::expression_or_expression_type);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ')':
+                            {
+                                push_token(token(end_function_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                break;
+                        }
+                        break;
+
+                    case path_state::argument:
+                        push_token(argument_arg, ec);
+                        if (ec) {return jmespath_expression();}
+                        state_stack_.pop_back();
+                        break;
+
+                    case path_state::expression_type:
+                        push_token(end_expression_type_arg, ec);
+                        push_token(argument_arg, ec);
+                        if (ec) {return jmespath_expression();}
+                        state_stack_.pop_back();
+                        break;
+
+                    case path_state::quoted_string: 
+                        switch (*p_)
+                        {
+                            case '\"':
+                                state_stack_.pop_back(); // quoted_string
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\\':
+                                state_stack_.emplace_back(path_state::quoted_string_escape_char);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+
+                    case path_state::unquoted_string: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                state_stack_.pop_back(); // unquoted_string
+                                advance_past_space_character(ec);
+                                break;
+                            default:
+                                if ((*p_ >= '0' && *p_ <= '9') || (*p_ >= 'A' && *p_ <= 'Z') || (*p_ >= 'a' && *p_ <= 'z') || (*p_ == '_'))
+                                {
+                                    buffer.push_back(*p_);
+                                    ++p_;
+                                    ++column_;
+                                }
+                                else
+                                {
+                                    state_stack_.pop_back(); // unquoted_string
+                                }
+                                break;
+                        };
+                        break;
+                    case path_state::raw_string_escape_char:
+                        switch (*p_)
+                        {
+                            case '\'':
+                                buffer.push_back(*p_);
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back('\\');
+                                buffer.push_back(*p_);
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                        }
+                        break;
+                    case path_state::quoted_string_escape_char:
+                        switch (*p_)
+                        {
+                            case '\"':
+                                buffer.push_back('\"');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case '\\': 
+                                buffer.push_back('\\');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case '/':
+                                buffer.push_back('/');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'b':
+                                buffer.push_back('\b');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'f':
+                                buffer.push_back('\f');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'n':
+                                buffer.push_back('\n');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'r':
+                                buffer.push_back('\r');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 't':
+                                buffer.push_back('\t');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'u':
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::escape_u1;
+                                break;
+                            default:
+                                ec = jmespath_errc::illegal_escaped_character;
+                                return jmespath_expression();
+                        }
+                        break;
+                    case path_state::escape_u1:
+                        cp = append_to_codepoint(0, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u2;
+                        break;
+                    case path_state::escape_u2:
+                        cp = append_to_codepoint(cp, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u3;
+                        break;
+                    case path_state::escape_u3:
+                        cp = append_to_codepoint(cp, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u4;
+                        break;
+                    case path_state::escape_u4:
+                        cp = append_to_codepoint(cp, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        if (unicode_traits::is_high_surrogate(cp))
+                        {
+                            ++p_;
+                            ++column_;
+                            state_stack_.back() = path_state::escape_expect_surrogate_pair1;
+                        }
+                        else
+                        {
+                            unicode_traits::convert(&cp, 1, buffer);
+                            ++p_;
+                            ++column_;
+                            state_stack_.pop_back();
+                        }
+                        break;
+                    case path_state::escape_expect_surrogate_pair1:
+                        switch (*p_)
+                        {
+                            case '\\': 
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::escape_expect_surrogate_pair2;
+                                break;
+                            default:
+                                ec = jmespath_errc::invalid_codepoint;
+                                return jmespath_expression();
+                        }
+                        break;
+                    case path_state::escape_expect_surrogate_pair2:
+                        switch (*p_)
+                        {
+                            case 'u': 
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::escape_u5;
+                                break;
+                            default:
+                                ec = jmespath_errc::invalid_codepoint;
+                                return jmespath_expression();
+                        }
+                        break;
+                    case path_state::escape_u5:
+                        cp2 = append_to_codepoint(0, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u6;
+                        break;
+                    case path_state::escape_u6:
+                        cp2 = append_to_codepoint(cp2, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u7;
+                        break;
+                    case path_state::escape_u7:
+                        cp2 = append_to_codepoint(cp2, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u8;
+                        break;
+                    case path_state::escape_u8:
+                    {
+                        cp2 = append_to_codepoint(cp2, *p_, ec);
+                        if (ec)
+                        {
+                            return jmespath_expression();
+                        }
+                        uint32_t codepoint = 0x10000 + ((cp & 0x3FF) << 10) + (cp2 & 0x3FF);
+                        unicode_traits::convert(&codepoint, 1, buffer);
+                        state_stack_.pop_back();
+                        ++p_;
+                        ++column_;
+                        break;
+                    }
+                    case path_state::raw_string: 
+                        switch (*p_)
+                        {
+                            case '\'':
+                            {
+                                push_token(token(literal_arg, Json(buffer)), ec);
+                                if (ec) {return jmespath_expression();}
+                                buffer.clear();
+                                state_stack_.pop_back(); // raw_string
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '\\':
+                                state_stack_.emplace_back(path_state::raw_string_escape_char);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+                    case path_state::literal: 
+                        switch (*p_)
+                        {
+                            case '`':
+                            {
+                                json_decoder<Json> decoder;
+                                basic_json_reader<char_type,string_source<char_type>> reader(buffer, decoder);
+                                std::error_code parse_ec;
+                                reader.read(parse_ec);
+                                if (parse_ec)
+                                {
+                                    ec = jmespath_errc::invalid_literal;
+                                    return jmespath_expression();
+                                }
+                                auto j = decoder.get_result();
+
+                                push_token(token(literal_arg, std::move(j)), ec);
+                                if (ec) {return jmespath_expression();}
+                                buffer.clear();
+                                state_stack_.pop_back(); // json_value
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '\\':
+                                if (p_+1 < end_input_)
+                                {
+                                    ++p_;
+                                    ++column_;
+                                    if (*p_ != '`')
+                                    {
+                                        buffer.push_back('\\');
+                                    }
+                                    buffer.push_back(*p_);
+                                }
+                                else
+                                {
+                                    ec = jmespath_errc::unexpected_end_of_input;
+                                    return jmespath_expression();
+                                }
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+                    case path_state::number:
+                        switch(*p_)
+                        {
+                            case '-':
+                                buffer.push_back(*p_);
+                                state_stack_.back() = path_state::digit;
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.back() = path_state::digit;
+                                break;
+                        }
+                        break;
+                    case path_state::digit:
+                        switch(*p_)
+                        {
+                            case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.pop_back(); // digit
+                                break;
+                        }
+                        break;
+
+                    case path_state::bracket_specifier:
+                        switch(*p_)
+                        {
+                            case '*':
+                                push_token(token(jsoncons::make_unique<list_projection>()), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::expect_rbracket;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ']': // []
+                                push_token(token(jsoncons::make_unique<flatten_projection>()), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); // bracket_specifier
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '?':
+                                push_token(token(begin_filter_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::filter;
+                                state_stack_.emplace_back(path_state::rhs_expression);
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ':': // slice_expression
+                                state_stack_.back() = path_state::rhs_slice_expression_stop ;
+                                state_stack_.emplace_back(path_state::number);
+                                ++p_;
+                                ++column_;
+                                break;
+                            // number
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                state_stack_.back() = path_state::index_or_slice_expression;
+                                state_stack_.emplace_back(path_state::number);
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_index_expression;
+                                return jmespath_expression();
+                        }
+                        break;
+                    case path_state::bracket_specifier_or_multi_select_list:
+                        switch(*p_)
+                        {
+                            case '*':
+                                if (p_+1 >= end_input_)
+                                {
+                                    ec = jmespath_errc::unexpected_end_of_input;
+                                    return jmespath_expression();
+                                }
+                                if (*(p_+1) == ']')
+                                {
+                                    state_stack_.back() = path_state::bracket_specifier;
+                                }
+                                else
+                                {
+                                    push_token(token(begin_multi_select_list_arg), ec);
+                                    if (ec) {return jmespath_expression();}
+                                    state_stack_.back() = path_state::multi_select_list;
+                                    state_stack_.emplace_back(path_state::lhs_expression);                                
+                                }
+                                break;
+                            case ']': // []
+                            case '?':
+                            case ':': // slice_expression
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                state_stack_.back() = path_state::bracket_specifier;
+                                break;
+                            default:
+                                push_token(token(begin_multi_select_list_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::multi_select_list;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                break;
+                        }
+                        break;
+
+                    case path_state::expect_multi_select_list:
+                        switch(*p_)
+                        {
+                            case ']':
+                            case '?':
+                            case ':':
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                ec = jmespath_errc::expected_multi_select_list;
+                                return jmespath_expression();
+                            case '*':
+                                push_token(token(jsoncons::make_unique<list_projection>()), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::expect_rbracket;
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                push_token(token(begin_multi_select_list_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::multi_select_list;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                break;
+                        }
+                        break;
+
+                    case path_state::multi_select_hash:
+                        switch(*p_)
+                        {
+                            case '*':
+                            case ']':
+                            case '?':
+                            case ':':
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                break;
+                            default:
+                                state_stack_.back() = path_state::key_val_expr;
+                                break;
+                        }
+                        break;
+
+                    case path_state::index_or_slice_expression:
+                        switch(*p_)
+                        {
+                            case ']':
+                            {
+                                if (buffer.empty())
+                                {
+                                    push_token(token(jsoncons::make_unique<flatten_projection>()), ec);
+                                    if (ec) {return jmespath_expression();}
+                                }
+                                else
+                                {
+                                    int64_t val{ 0 };
+                                    auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), val);
+                                    if (!r)
+                                    {
+                                        ec = jmespath_errc::invalid_number;
+                                        return jmespath_expression();
+                                    }
+                                    push_token(token(jsoncons::make_unique<index_selector>(val)), ec);
+                                    if (ec) {return jmespath_expression();}
+
+                                    buffer.clear();
+                                }
+                                state_stack_.pop_back(); // bracket_specifier
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case ':':
+                            {
+                                if (!buffer.empty())
+                                {
+                                    int64_t val;
+                                    auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), val);
+                                    if (!r)
+                                    {
+                                        ec = jmespath_errc::invalid_number;
+                                        return jmespath_expression();
+                                    }
+                                    slic.start_ = val;
+                                    buffer.clear();
+                                }
+                                state_stack_.back() = path_state::rhs_slice_expression_stop;
+                                state_stack_.emplace_back(path_state::number);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jmespath_errc::expected_rbracket;
+                                return jmespath_expression();
+                        }
+                        break;
+                    case path_state::rhs_slice_expression_stop :
+                    {
+                        if (!buffer.empty())
+                        {
+                            int64_t val{ 0 };
+                            auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), val);
+                            if (!r)
+                            {
+                                ec = jmespath_errc::invalid_number;
+                                return jmespath_expression();
+                            }
+                            slic.stop_ = jsoncons::optional<int64_t>(val);
+                            buffer.clear();
+                        }
+                        switch(*p_)
+                        {
+                            case ']':
+                                push_token(token(jsoncons::make_unique<slice_projection>(slic)), ec);
+                                if (ec) {return jmespath_expression();}
+                                slic = slice{};
+                                state_stack_.pop_back(); // bracket_specifier2
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ':':
+                                state_stack_.back() = path_state::rhs_slice_expression_step;
+                                state_stack_.emplace_back(path_state::number);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_rbracket;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::rhs_slice_expression_step:
+                    {
+                        if (!buffer.empty())
+                        {
+                            int64_t val{ 0 };
+                            auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), val);
+                            if (!r)
+                            {
+                                ec = jmespath_errc::invalid_number;
+                                return jmespath_expression();
+                            }
+                            if (val == 0)
+                            {
+                                ec = jmespath_errc::step_cannot_be_zero;
+                                return jmespath_expression();
+                            }
+                            slic.step_ = val;
+                            buffer.clear();
+                        }
+                        switch(*p_)
+                        {
+                            case ']':
+                                push_token(token(jsoncons::make_unique<slice_projection>(slic)), ec);
+                                if (ec) {return jmespath_expression();}
+                                buffer.clear();
+                                slic = slice{};
+                                state_stack_.pop_back(); // rhs_slice_expression_step
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_rbracket;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::expect_rbracket:
+                    {
+                        switch(*p_)
+                        {
+                            case ']':
+                                state_stack_.pop_back(); // expect_rbracket
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_rbracket;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::expect_rparen:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case ')':
+                                ++p_;
+                                ++column_;
+                                push_token(rparen_arg, ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::rhs_expression;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_rparen;
+                                return jmespath_expression();
+                        }
+                        break;
+                    case path_state::key_val_expr: 
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::expect_colon;
+                                state_stack_.emplace_back(path_state::key_expr);
+                                state_stack_.emplace_back(path_state::quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\'':
+                                state_stack_.back() = path_state::expect_colon;
+                                state_stack_.emplace_back(path_state::raw_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                if ((*p_ >= 'A' && *p_ <= 'Z') || (*p_ >= 'a' && *p_ <= 'z') || (*p_ == '_'))
+                                {
+                                    state_stack_.back() = path_state::expect_colon;
+                                    state_stack_.emplace_back(path_state::key_expr);
+                                    state_stack_.emplace_back(path_state::unquoted_string);
+                                    buffer.push_back(*p_);
+                                    ++p_;
+                                    ++column_;
+                                }
+                                else
+                                {
+                                    ec = jmespath_errc::expected_key;
+                                    return jmespath_expression();
+                                }
+                                break;
+                        };
+                        break;
+                    }
+                    case path_state::cmp_lt_or_lte:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(token(resources_.get_lte_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                push_token(token(resources_.get_lt_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::cmp_gt_or_gte:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(token(resources_.get_gte_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                push_token(token(resources_.get_gt_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::cmp_eq:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(token(resources_.get_eq_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_comparator;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::cmp_ne:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(token(resources_.get_ne_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_comparator;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::expect_dot:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case '.':
+                                state_stack_.pop_back(); // expect_dot
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_dot;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::expect_pipe_or_or:
+                    {
+                        switch(*p_)
+                        {
+                            case '|':
+                                push_token(token(resources_.get_or_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                push_token(token(pipe_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); 
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::expect_and:
+                    {
+                        switch(*p_)
+                        {
+                            case '&':
+                                push_token(token(resources_.get_and_operator()), ec);
+                                push_token(token(current_node_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back(); // expect_and
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_and;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::multi_select_list:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case ',':
+                                push_token(token(separator_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                break;
+                            case '.':
+                                state_stack_.emplace_back(path_state::sub_expression);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '|':
+                            {
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                state_stack_.emplace_back(path_state::expect_pipe_or_or);
+                                break;
+                            }
+                            case ']':
+                            {
+                                push_token(token(end_multi_select_list_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jmespath_errc::expected_rbracket;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::filter:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case ']':
+                            {
+                                push_token(token(end_filter_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jmespath_errc::expected_rbracket;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::expect_rbrace:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case ',':
+                                push_token(token(separator_arg), ec);
+                                if (ec) {return jmespath_expression();}
+                                state_stack_.back() = path_state::key_val_expr; 
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                            case '{':
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                break;
+                            case '.':
+                                state_stack_.emplace_back(path_state::sub_expression);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '}':
+                            {
+                                state_stack_.pop_back();
+                                push_token(end_multi_select_hash_arg, ec);
+                                if (ec) {return jmespath_expression();}
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jmespath_errc::expected_rbrace;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                    case path_state::expect_colon:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character(ec);
+                                break;
+                            case ':':
+                                state_stack_.back() = path_state::expect_rbrace;
+                                state_stack_.emplace_back(path_state::lhs_expression);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jmespath_errc::expected_colon;
+                                return jmespath_expression();
+                        }
+                        break;
+                    }
+                }
+                
+            }
+
+            if (state_stack_.empty())
+            {
+                ec = jmespath_errc::syntax_error;
+                return jmespath_expression();
+            }
+            while (state_stack_.size() > 1)
+            {
+                switch (state_stack_.back())
+                {
+                    case path_state::rhs_expression:
+                        if (state_stack_.size() > 1)
+                        {
+                            state_stack_.pop_back();
+                        }
+                        else
+                        {
+                            ec = jmespath_errc::syntax_error;
+                            return jmespath_expression();
+                        }
+                        break;
+                    case path_state::val_expr:
+                        push_token(token(jsoncons::make_unique<identifier_selector>(buffer)), ec);
+                        if (ec) {return jmespath_expression();}
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::identifier_or_function_expr:
+                        push_token(token(jsoncons::make_unique<identifier_selector>(buffer)), ec);
+                        if (ec) {return jmespath_expression();}
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::unquoted_string: 
+                        state_stack_.pop_back(); 
+                        break;
+                    default:
+                        ec = jmespath_errc::syntax_error;
+                        return jmespath_expression();
+                        break;
+                }
+            }
+
+            if (!(state_stack_.size() == 1 && state_stack_.back() == path_state::rhs_expression))
+            {
+                ec = jmespath_errc::unexpected_end_of_input;
+                return jmespath_expression();
+            }
+
+            state_stack_.pop_back();
+
+            push_token(end_of_expression_arg, ec);
+            if (ec) {return jmespath_expression();}
+
+            //for (auto& t : output_stack_)
+            //{
+            //    std::cout << t.to_string() << std::endl;
+            //}
+
+            return jmespath_expression(std::move(resources_), std::move(output_stack_));
+        }
+
+        void advance_past_space_character(std::error_code& ec)
+        {
+            switch (*p_)
+            {
+                case ' ':case '\t':
+                    ++p_;
+                    ++column_;
+                    break;
+                case '\r':
+                    if (p_+1 >= end_input_)
+                    {
+                        ec = jmespath_errc::unexpected_end_of_input;
+                        return;
+                    }
+                    if (*(p_+1) == '\n')
+                        ++p_;
+                    ++line_;
+                    column_ = 1;
+                    ++p_;
+                    break;
+                case '\n':
+                    ++line_;
+                    column_ = 1;
+                    ++p_;
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        void unwind_rparen(std::error_code& ec)
+        {
+            auto it = operator_stack_.rbegin();
+            while (it != operator_stack_.rend() && !it->is_lparen())
+            {
+                output_stack_.emplace_back(std::move(*it));
+                ++it;
+            }
+            if (it == operator_stack_.rend())
+            {
+                ec = jmespath_errc::unbalanced_parentheses;
+                return;
+            }
+            ++it;
+            operator_stack_.erase(it.base(),operator_stack_.end());
+        }
+
+        void push_token(token&& tok, std::error_code& ec)
+        {
+            switch (tok.type())
+            {
+                case token_kind::end_filter:
+                {
+                    unwind_rparen(ec);
+                    std::vector<token> toks;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->type() != token_kind::begin_filter)
+                    {
+                        toks.emplace_back(std::move(*it));
+                        ++it;
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jmespath_errc::unbalanced_braces;
+                        return;
+                    }
+                    if (toks.back().type() != token_kind::literal)
+                    {
+                        toks.emplace_back(current_node_arg);
+                    }
+                    std::reverse(toks.begin(), toks.end());
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+
+                    if (!output_stack_.empty() && output_stack_.back().is_projection() && 
+                        (tok.precedence_level() < output_stack_.back().precedence_level() ||
+                        (tok.precedence_level() == output_stack_.back().precedence_level() && tok.is_right_associative())))
+                    {
+                        output_stack_.back().expression_->add_expression(jsoncons::make_unique<filter_expression>(std::move(toks)));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token(jsoncons::make_unique<filter_expression>(std::move(toks))));
+                    }
+                    break;
+                }
+                case token_kind::end_multi_select_list:
+                {
+                    unwind_rparen(ec);
+                    std::vector<std::vector<token>> vals;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->type() != token_kind::begin_multi_select_list)
+                    {
+                        std::vector<token> toks;
+                        do
+                        {
+                            toks.emplace_back(std::move(*it));
+                            ++it;
+                        } while (it != output_stack_.rend() && it->type() != token_kind::begin_multi_select_list && it->type() != token_kind::separator);
+                        if (it->type() == token_kind::separator)
+                        {
+                            ++it;
+                        }
+                        if (toks.back().type() != token_kind::literal)
+                        {
+                            toks.emplace_back(current_node_arg);
+                        }
+                        std::reverse(toks.begin(), toks.end());
+                        vals.emplace_back(std::move(toks));
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jmespath_errc::unbalanced_braces;
+                        return;
+                    }
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+                    std::reverse(vals.begin(), vals.end());
+                    if (!output_stack_.empty() && output_stack_.back().is_projection() && 
+                        (tok.precedence_level() < output_stack_.back().precedence_level() ||
+                        (tok.precedence_level() == output_stack_.back().precedence_level() && tok.is_right_associative())))
+                    {
+                        output_stack_.back().expression_->add_expression(jsoncons::make_unique<multi_select_list>(std::move(vals)));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token(jsoncons::make_unique<multi_select_list>(std::move(vals))));
+                    }
+                    break;
+                }
+                case token_kind::end_multi_select_hash:
+                {
+                    unwind_rparen(ec);
+                    std::vector<key_tokens> key_toks;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->type() != token_kind::begin_multi_select_hash)
+                    {
+                        std::vector<token> toks;
+                        do
+                        {
+                            toks.emplace_back(std::move(*it));
+                            ++it;
+                        } while (it != output_stack_.rend() && it->type() != token_kind::key);
+                        JSONCONS_ASSERT(it->is_key());
+                        auto key = std::move(it->key_);
+                        ++it;
+                        if (it->type() == token_kind::separator)
+                        {
+                            ++it;
+                        }
+                        if (toks.back().type() != token_kind::literal)
+                        {
+                            toks.emplace_back(current_node_arg);
+                        }
+                        std::reverse(toks.begin(), toks.end());
+                        key_toks.emplace_back(std::move(key), std::move(toks));
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jmespath_errc::unbalanced_braces;
+                        return;
+                    }
+                    std::reverse(key_toks.begin(), key_toks.end());
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+
+                    if (!output_stack_.empty() && output_stack_.back().is_projection() && 
+                        (tok.precedence_level() < output_stack_.back().precedence_level() ||
+                        (tok.precedence_level() == output_stack_.back().precedence_level() && tok.is_right_associative())))
+                    {
+                        output_stack_.back().expression_->add_expression(jsoncons::make_unique<multi_select_hash>(std::move(key_toks)));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token(jsoncons::make_unique<multi_select_hash>(std::move(key_toks))));
+                    }
+                    break;
+                }
+                case token_kind::end_expression_type:
+                {
+                    std::vector<token> toks;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->type() != token_kind::begin_expression_type)
+                    {
+                        toks.emplace_back(std::move(*it));
+                        ++it;
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        JSONCONS_THROW(json_runtime_error<std::runtime_error>("Unbalanced braces"));
+                    }
+                    if (toks.back().type() != token_kind::literal)
+                    {
+                        toks.emplace_back(current_node_arg);
+                    }
+                    std::reverse(toks.begin(), toks.end());
+                    output_stack_.erase(it.base(),output_stack_.end());
+                    output_stack_.emplace_back(token(jsoncons::make_unique<function_expression>(std::move(toks))));
+                    break;
+                }
+                case token_kind::literal:
+                    if (!output_stack_.empty() && output_stack_.back().type() == token_kind::current_node)
+                    {
+                        output_stack_.back() = std::move(tok);
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(std::move(tok));
+                    }
+                    break;
+                case token_kind::expression:
+                    if (!output_stack_.empty() && output_stack_.back().is_projection() && 
+                        (tok.precedence_level() < output_stack_.back().precedence_level() ||
+                        (tok.precedence_level() == output_stack_.back().precedence_level() && tok.is_right_associative())))
+                    {
+                        output_stack_.back().expression_->add_expression(std::move(tok.expression_));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(std::move(tok));
+                    }
+                    break;
+                case token_kind::rparen:
+                    {
+                        unwind_rparen(ec);
+                        break;
+                    }
+                case token_kind::end_function:
+                    {
+                        unwind_rparen(ec);
+                        std::vector<token> toks;
+                        auto it = output_stack_.rbegin();
+                        std::size_t arg_count = 0;
+                        while (it != output_stack_.rend() && it->type() != token_kind::function)
+                        {
+                            if (it->type() == token_kind::argument)
+                            {
+                                ++arg_count;
+                            }
+                            toks.emplace_back(std::move(*it));
+                            ++it;
+                        }
+                        if (it == output_stack_.rend())
+                        {
+                            ec = jmespath_errc::unbalanced_parentheses;
+                            return;
+                        }
+                        if (it->arity() && arg_count != *(it->arity()))
+                        {
+                            ec = jmespath_errc::invalid_arity;
+                            return;
+                        }
+                        if (toks.back().type() != token_kind::literal)
+                        {
+                            toks.emplace_back(current_node_arg);
+                        }
+                        std::reverse(toks.begin(), toks.end());
+                        toks.push_back(std::move(*it));
+                        ++it;
+                        output_stack_.erase(it.base(),output_stack_.end());
+
+                        if (!output_stack_.empty() && output_stack_.back().is_projection() && 
+                            (tok.precedence_level() < output_stack_.back().precedence_level() ||
+                            (tok.precedence_level() == output_stack_.back().precedence_level() && tok.is_right_associative())))
+                        {
+                            output_stack_.back().expression_->add_expression(jsoncons::make_unique<function_expression>(std::move(toks)));
+                        }
+                        else
+                        {
+                            output_stack_.emplace_back(token(jsoncons::make_unique<function_expression>(std::move(toks))));
+                        }
+                        break;
+                    }
+                case token_kind::end_of_expression:
+                    {
+                        auto it = operator_stack_.rbegin();
+                        while (it != operator_stack_.rend())
+                        {
+                            output_stack_.emplace_back(std::move(*it));
+                            ++it;
+                        }
+                        operator_stack_.clear();
+                        break;
+                    }
+                case token_kind::unary_operator:
+                case token_kind::binary_operator:
+                {
+                    if (operator_stack_.empty() || operator_stack_.back().is_lparen())
+                    {
+                        operator_stack_.emplace_back(std::move(tok));
+                    }
+                    else if (tok.precedence_level() < operator_stack_.back().precedence_level()
+                             || (tok.precedence_level() == operator_stack_.back().precedence_level() && tok.is_right_associative()))
+                    {
+                        operator_stack_.emplace_back(std::move(tok));
+                    }
+                    else
+                    {
+                        auto it = operator_stack_.rbegin();
+                        while (it != operator_stack_.rend() && it->is_operator()
+                               && (tok.precedence_level() > it->precedence_level()
+                             || (tok.precedence_level() == it->precedence_level() && tok.is_right_associative())))
+                        {
+                            output_stack_.emplace_back(std::move(*it));
+                            ++it;
+                        }
+
+                        operator_stack_.erase(it.base(),operator_stack_.end());
+                        operator_stack_.emplace_back(std::move(tok));
+                    }
+                    break;
+                }
+                case token_kind::separator:
+                {
+                    unwind_rparen(ec);
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token(lparen_arg));
+                    break;
+                }
+                case token_kind::begin_filter:
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token(lparen_arg));
+                    break;
+                case token_kind::begin_multi_select_list:
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token(lparen_arg));
+                    break;
+                case token_kind::begin_multi_select_hash:
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token(lparen_arg));
+                    break;
+                case token_kind::function:
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token(lparen_arg));
+                    break;
+                case token_kind::current_node:
+                    output_stack_.emplace_back(std::move(tok));
+                    break;
+                case token_kind::key:
+                case token_kind::pipe:
+                case token_kind::argument:
+                case token_kind::begin_expression_type:
+                    output_stack_.emplace_back(std::move(tok));
+                    break;
+                case token_kind::lparen:
+                    operator_stack_.emplace_back(std::move(tok));
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        uint32_t append_to_codepoint(uint32_t cp, int c, std::error_code& ec)
+        {
+            cp *= 16;
+            if (c >= '0'  &&  c <= '9')
+            {
+                cp += c - '0';
+            }
+            else if (c >= 'a'  &&  c <= 'f')
+            {
+                cp += c - 'a' + 10;
+            }
+            else if (c >= 'A'  &&  c <= 'F')
+            {
+                cp += c - 'A' + 10;
+            }
+            else
+            {
+                ec = jmespath_errc::invalid_codepoint;
+            }
+            return cp;
+        }
+    };
+
+    } // detail
+
+    template <class Json>
+    using jmespath_expression = typename jsoncons::jmespath::detail::jmespath_evaluator<Json,const Json&>::jmespath_expression;
+
+    template<class Json>
+    Json search(const Json& doc, const typename Json::string_view_type& path)
+    {
+        jsoncons::jmespath::detail::jmespath_evaluator<Json,const Json&> evaluator;
+        std::error_code ec;
+        auto expr = evaluator.compile(path.data(), path.size(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jmespath_error(ec, evaluator.line(), evaluator.column()));
+        }
+        auto result = expr.evaluate(doc, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jmespath_error(ec));
+        }
+        return result;
+    }
+
+    template<class Json>
+    Json search(const Json& doc, const typename Json::string_view_type& path, std::error_code& ec)
+    {
+        jsoncons::jmespath::detail::jmespath_evaluator<Json,const Json&> evaluator;
+        auto expr = evaluator.compile(path.data(), path.size(), ec);
+        if (ec)
+        {
+            return Json::null();
+        }
+        auto result = expr.evaluate(doc, ec);
+        if (ec)
+        {
+            return Json::null();
+        }
+        return result;
+    }
+
+    template <class Json>
+    jmespath_expression<Json> make_expression(const typename json::string_view_type& expr)
+    {
+        return jmespath_expression<Json>::compile(expr);
+    }
+
+    template <class Json>
+    jmespath_expression<Json> make_expression(const typename json::string_view_type& expr,
+                                              std::error_code& ec)
+    {
+        return jmespath_expression<Json>::compile(expr, ec);
+    }
+
+
+} // namespace jmespath
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jmespath/jmespath_error.hpp b/include/jsoncons_ext/jmespath/jmespath_error.hpp
new file mode 100644
index 0000000..6422c65
--- /dev/null
+++ b/include/jsoncons_ext/jmespath/jmespath_error.hpp
@@ -0,0 +1,215 @@
+/// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JMESPATH_JMESPATH_ERROR_HPP
+#define JSONCONS_JMESPATH_JMESPATH_ERROR_HPP
+
+#include <jsoncons/json_exception.hpp>
+#include <system_error>
+
+namespace jsoncons { namespace jmespath {
+
+    class jmespath_error : public std::system_error, public virtual json_exception
+    {
+        std::size_t line_number_;
+        std::size_t column_number_;
+        mutable std::string what_;
+    public:
+        jmespath_error(std::error_code ec)
+            : std::system_error(ec), line_number_(0), column_number_(0)
+        {
+        }
+        jmespath_error(std::error_code ec, const std::string& what_arg)
+            : std::system_error(ec, what_arg), line_number_(0), column_number_(0)
+        {
+        }
+        jmespath_error(std::error_code ec, std::size_t position)
+            : std::system_error(ec), line_number_(0), column_number_(position)
+        {
+        }
+        jmespath_error(std::error_code ec, std::size_t line, std::size_t column)
+            : std::system_error(ec), line_number_(line), column_number_(column)
+        {
+        }
+        jmespath_error(const jmespath_error& other) = default;
+
+        jmespath_error(jmespath_error&& other) = default;
+
+        const char* what() const noexcept override
+        {
+            if (what_.empty())
+            {
+                JSONCONS_TRY
+                {
+                    what_.append(std::system_error::what());
+                    if (line_number_ != 0 && column_number_ != 0)
+                    {
+                        what_.append(" at line ");
+                        what_.append(std::to_string(line_number_));
+                        what_.append(" and column ");
+                        what_.append(std::to_string(column_number_));
+                    }
+                    else if (column_number_ != 0)
+                    {
+                        what_.append(" at position ");
+                        what_.append(std::to_string(column_number_));
+                    }
+                    return what_.c_str();
+                }
+                JSONCONS_CATCH(...)
+                {
+                    return std::system_error::what();
+                }
+            }
+            else
+            {
+                return what_.c_str();
+            }
+        }
+
+        std::size_t line() const noexcept
+        {
+            return line_number_;
+        }
+
+        std::size_t column() const noexcept
+        {
+            return column_number_;
+        }
+    };
+
+enum class jmespath_errc 
+{
+    success = 0,
+    expected_identifier,
+    expected_index,
+    expected_A_Za_Z_,
+    expected_rbracket,
+    expected_rparen,
+    expected_rbrace,
+    expected_colon,
+    expected_dot,
+    expected_or,
+    expected_and,
+    expected_multi_select_list,
+    invalid_number,
+    invalid_literal,
+    expected_comparator,
+    expected_key,
+    invalid_argument,
+    unknown_function,
+    invalid_type,
+    unexpected_end_of_input,
+    step_cannot_be_zero,
+    syntax_error,
+    invalid_codepoint,
+    illegal_escaped_character,
+    unbalanced_parentheses,
+    unbalanced_braces,
+    invalid_arity,
+    identifier_not_found,
+    expected_index_expression,
+    unknown_error 
+};
+
+class jmespath_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/jmespath";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<jmespath_errc>(ev))
+        {
+            case jmespath_errc::expected_identifier:
+                return "Expected identifier";
+            case jmespath_errc::expected_index:
+                return "Expected index";
+            case jmespath_errc::expected_A_Za_Z_:
+                return "Expected A-Z, a-z, or _";
+            case jmespath_errc::expected_rbracket:
+                return "Expected ]";
+            case jmespath_errc::expected_rparen:
+                return "Expected )";
+            case jmespath_errc::expected_rbrace:
+                return "Expected }";
+            case jmespath_errc::expected_colon:
+                return "Expected :";
+            case jmespath_errc::expected_dot:
+                return "Expected \".\"";
+            case jmespath_errc::expected_or:
+                return "Expected \"||\"";
+            case jmespath_errc::expected_and:
+                return "Expected \"&&\"";
+            case jmespath_errc::expected_multi_select_list:
+                return "Expected multi-select-list";
+            case jmespath_errc::invalid_number:
+                return "Invalid number";
+            case jmespath_errc::invalid_literal:
+                return "Invalid literal";
+            case jmespath_errc::expected_comparator:
+                return "Expected <, <=, ==, >=, > or !=";
+            case jmespath_errc::expected_key:
+                return "Expected key";
+            case jmespath_errc::invalid_argument:
+                return "Invalid argument type";
+            case jmespath_errc::unknown_function:
+                return "Unknown function";
+            case jmespath_errc::invalid_type:
+                return "Invalid type";
+            case jmespath_errc::unexpected_end_of_input:
+                return "Unexpected end of jmespath input";
+            case jmespath_errc::step_cannot_be_zero:
+                return "Slice step cannot be zero";
+            case jmespath_errc::syntax_error:
+                return "Syntax error";
+            case jmespath_errc::invalid_codepoint:
+                return "Invalid codepoint";
+            case jmespath_errc::illegal_escaped_character:
+                return "Illegal escaped character";
+            case jmespath_errc::unbalanced_parentheses:
+                return "Unbalanced parentheses";
+            case jmespath_errc::unbalanced_braces:
+                return "Unbalanced braces";
+            case jmespath_errc::invalid_arity:
+                return "Function called with wrong number of arguments";
+            case jmespath_errc::identifier_not_found:
+                return "Identifier not found";
+            case jmespath_errc::expected_index_expression:
+                return "Expected index expression";
+            case jmespath_errc::unknown_error:
+            default:
+                return "Unknown jmespath parser error";
+        }
+    }
+};
+
+inline
+const std::error_category& jmespath_error_category()
+{
+  static jmespath_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(jmespath_errc result)
+{
+    return std::error_code(static_cast<int>(result),jmespath_error_category());
+}
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::jmespath::jmespath_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/jsonpatch/jsonpatch.hpp b/include/jsoncons_ext/jsonpatch/jsonpatch.hpp
new file mode 100644
index 0000000..ab4ace7
--- /dev/null
+++ b/include/jsoncons_ext/jsonpatch/jsonpatch.hpp
@@ -0,0 +1,579 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATCH_JSONPATCH_HPP
+#define JSONCONS_JSONPATCH_JSONPATCH_HPP
+
+#include <string>
+#include <vector> 
+#include <memory>
+#include <algorithm> // std::min
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonpatch/jsonpatch_error.hpp>
+
+namespace jsoncons { namespace jsonpatch {
+
+namespace detail {
+
+    template <class CharT>
+    struct jsonpatch_names
+    {
+        static std::basic_string<CharT> test_name()
+        {
+            static std::basic_string<CharT> name{'t','e','s','t'};
+            return name;
+        }
+        static std::basic_string<CharT> add_name()
+        {
+            static std::basic_string<CharT> name{'a','d','d'};
+            return name;
+        }
+        static std::basic_string<CharT> remove_name()
+        {
+            static std::basic_string<CharT> name{'r','e','m','o','v','e'};
+            return name;
+        }
+        static std::basic_string<CharT> replace_name()
+        {
+            static std::basic_string<CharT> name{'r','e','p','l','a','c','e'};
+            return name;
+        }
+        static std::basic_string<CharT> move_name()
+        {
+            static std::basic_string<CharT> name{'m','o','v','e'};
+            return name;
+        }
+        static std::basic_string<CharT> copy_name()
+        {
+            static std::basic_string<CharT> name{'c','o','p','y'};
+            return name;
+        }
+        static std::basic_string<CharT> op_name()
+        {
+            static std::basic_string<CharT> name{'o','p'};
+            return name;
+        }
+        static std::basic_string<CharT> path_name()
+        {
+            static std::basic_string<CharT> name{'p','a','t','h'};
+            return name;
+        }
+        static std::basic_string<CharT> from_name()
+        {
+            static std::basic_string<CharT> name{'f','r','o','m'};
+            return name;
+        }
+        static std::basic_string<CharT> value_name()
+        {
+            static std::basic_string<CharT> name{'v','a','l','u','e'};
+            return name;
+        }
+        static std::basic_string<CharT> dash_name()
+        {
+            static std::basic_string<CharT> name{'-'};
+            return name;
+        }
+    };
+
+    template<class Json>
+    jsonpointer::basic_json_pointer<typename Json::char_type> definite_path(const Json& root, jsonpointer::basic_json_pointer<typename Json::char_type>& location)
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+
+        auto rit = location.rbegin();
+        if (rit == location.rend())
+        {
+            return location;
+        }
+
+        if (*rit != jsonpatch_names<char_type>::dash_name())
+        {
+            return location;
+        }
+
+        std::vector<string_type> tokens;
+        for (auto it = location.begin(); it != location.rbegin().base()-1; ++it)
+        {
+            tokens.push_back(*it);
+        }
+        jsonpointer::basic_json_pointer<char_type> pointer(tokens);
+
+        std::error_code ec;
+
+        Json val = jsonpointer::get(root, pointer, ec);
+        if (ec || !val.is_array())
+        {
+            return location;
+        }
+        string_type last_token;
+        jsoncons::detail::from_integer(val.size(), last_token);
+        tokens.emplace_back(std::move(last_token));
+
+        return jsonpointer::basic_json_pointer<char_type>(std::move(tokens));
+    }
+
+    enum class op_type {add,remove,replace};
+    enum class state_type {begin,abort,commit};
+
+    template <class Json>
+    struct operation_unwinder
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+        using json_pointer_type = jsonpointer::basic_json_pointer<char_type>;
+
+        struct entry
+        {
+            op_type op;
+            json_pointer_type path;
+            Json value;
+
+            entry(op_type op, const json_pointer_type& path, const Json& value)
+                : op(op), path(path), value(value)
+            {
+            }
+
+            entry(const entry&) = default;
+
+            entry(entry&&) = default;
+
+            entry& operator=(const entry&) = default;
+
+            entry& operator=(entry&&) = default;
+        };
+
+        Json& target;
+        state_type state;
+        std::vector<entry> stack;
+
+        operation_unwinder(Json& j)
+            : target(j), state(state_type::begin)
+        {
+        }
+
+        ~operation_unwinder() noexcept
+        {
+            std::error_code ec;
+            if (state != state_type::commit)
+            {
+                for (auto it = stack.rbegin(); it != stack.rend(); ++it)
+                {
+                    if (it->op == op_type::add)
+                    {
+                        jsonpointer::add(target,it->path,it->value,ec);
+                        if (ec)
+                        {
+                            //std::cout << "add: " << it->path << std::endl;
+                            break;
+                        }
+                    }
+                    else if (it->op == op_type::remove)
+                    {
+                        jsonpointer::remove(target,it->path,ec);
+                        if (ec)
+                        {
+                            //std::cout << "remove: " << it->path << std::endl;
+                            break;
+                        }
+                    }
+                    else if (it->op == op_type::replace)
+                    {
+                        jsonpointer::replace(target,it->path,it->value,ec);
+                        if (ec)
+                        {
+                            //std::cout << "replace: " << it->path << std::endl;
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+    };
+
+    template <class Json>
+    Json from_diff(const Json& source, const Json& target, const typename Json::string_view_type& path)
+    {
+        using char_type = typename Json::char_type;
+
+        Json result = typename Json::array();
+
+        if (source == target)
+        {
+            return result;
+        }
+
+        if (source.is_array() && target.is_array())
+        {
+            std::size_t common = (std::min)(source.size(),target.size());
+            for (std::size_t i = 0; i < common; ++i)
+            {
+                std::basic_string<char_type> ss(path); 
+                ss.push_back('/');
+                jsoncons::detail::from_integer(i,ss);
+                auto temp_diff = from_diff(source[i],target[i],ss);
+                result.insert(result.array_range().end(),temp_diff.array_range().begin(),temp_diff.array_range().end());
+            }
+            // Element in source, not in target - remove
+            for (std::size_t i = source.size(); i-- > target.size();)
+            {
+                std::basic_string<char_type> ss(path); 
+                ss.push_back('/');
+                jsoncons::detail::from_integer(i,ss);
+                Json val(json_object_arg);
+                val.insert_or_assign(jsonpatch_names<char_type>::op_name(), jsonpatch_names<char_type>::remove_name());
+                val.insert_or_assign(jsonpatch_names<char_type>::path_name(), ss);
+                result.push_back(std::move(val));
+            }
+            // Element in target, not in source - add, 
+            // Fix contributed by Alexander rog13
+            for (std::size_t i = source.size(); i < target.size(); ++i)
+            {
+                const auto& a = target[i];
+                std::basic_string<char_type> ss(path); 
+                ss.push_back('/');
+                jsoncons::detail::from_integer(i,ss);
+                Json val(json_object_arg);
+                val.insert_or_assign(jsonpatch_names<char_type>::op_name(), jsonpatch_names<char_type>::add_name());
+                val.insert_or_assign(jsonpatch_names<char_type>::path_name(), ss);
+                val.insert_or_assign(jsonpatch_names<char_type>::value_name(), a);
+                result.push_back(std::move(val));
+            }
+        }
+        else if (source.is_object() && target.is_object())
+        {
+            for (const auto& a : source.object_range())
+            {
+                std::basic_string<char_type> ss(path);
+                ss.push_back('/'); 
+                jsonpointer::escape(a.key(),ss);
+                auto it = target.find(a.key());
+                if (it != target.object_range().end())
+                {
+                    auto temp_diff = from_diff(a.value(),it->value(),ss);
+                    result.insert(result.array_range().end(),temp_diff.array_range().begin(),temp_diff.array_range().end());
+                }
+                else
+                {
+                    Json val(json_object_arg);
+                    val.insert_or_assign(jsonpatch_names<char_type>::op_name(), jsonpatch_names<char_type>::remove_name());
+                    val.insert_or_assign(jsonpatch_names<char_type>::path_name(), ss);
+                    result.push_back(std::move(val));
+                }
+            }
+            for (const auto& a : target.object_range())
+            {
+                auto it = source.find(a.key());
+                if (it == source.object_range().end())
+                {
+                    std::basic_string<char_type> ss(path); 
+                    ss.push_back('/');
+                    jsonpointer::escape(a.key(),ss);
+                    Json val(json_object_arg);
+                    val.insert_or_assign(jsonpatch_names<char_type>::op_name(), jsonpatch_names<char_type>::add_name());
+                    val.insert_or_assign(jsonpatch_names<char_type>::path_name(), ss);
+                    val.insert_or_assign(jsonpatch_names<char_type>::value_name(), a.value());
+                    result.push_back(std::move(val));
+                }
+            }
+        }
+        else
+        {
+            Json val(json_object_arg);
+            val.insert_or_assign(jsonpatch_names<char_type>::op_name(), jsonpatch_names<char_type>::replace_name());
+            val.insert_or_assign(jsonpatch_names<char_type>::path_name(), path);
+            val.insert_or_assign(jsonpatch_names<char_type>::value_name(), target);
+            result.push_back(std::move(val));
+        }
+
+        return result;
+    }
+}
+
+template <class Json>
+void apply_patch(Json& target, const Json& patch, std::error_code& ec)
+{
+    using char_type = typename Json::char_type;
+    using string_type = std::basic_string<char_type>;
+    using json_pointer_type = jsonpointer::basic_json_pointer<char_type>;
+
+   jsoncons::jsonpatch::detail::operation_unwinder<Json> unwinder(target);
+   std::error_code local_ec;
+
+    // Validate
+     
+    for (const auto& operation : patch.array_range())
+    {
+        unwinder.state =jsoncons::jsonpatch::detail::state_type::begin;
+
+        auto it_op = operation.find(detail::jsonpatch_names<char_type>::op_name());
+        if (it_op == operation.object_range().end())
+        {
+            ec = jsonpatch_errc::invalid_patch;
+            unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+            return;
+        }
+        string_type op = it_op->value().template as<string_type>();
+
+        auto it_path = operation.find(detail::jsonpatch_names<char_type>::path_name());
+        if (it_path == operation.object_range().end())
+        {
+            ec = jsonpatch_errc::invalid_patch;
+            unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+            return;
+        }
+        string_type path = it_path->value().template as<string_type>();
+        auto location = json_pointer_type::parse(path, local_ec);
+        if (local_ec)
+        {
+            ec = jsonpatch_errc::invalid_patch;
+            unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+            return;
+        }
+
+        if (op ==jsoncons::jsonpatch::detail::jsonpatch_names<char_type>::test_name())
+        {
+            Json val = jsonpointer::get(target,location,local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::test_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            auto it_value = operation.find(detail::jsonpatch_names<char_type>::value_name());
+            if (it_value == operation.object_range().end())
+            {
+                ec = jsonpatch_errc::invalid_patch;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            if (val != it_value->value())
+            {
+                ec = jsonpatch_errc::test_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+        }
+        else if (op ==jsoncons::jsonpatch::detail::jsonpatch_names<char_type>::add_name())
+        {
+            auto it_value = operation.find(detail::jsonpatch_names<char_type>::value_name());
+            if (it_value == operation.object_range().end())
+            {
+                ec = jsonpatch_errc::invalid_patch;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            Json val = it_value->value();
+            auto npath = jsonpatch::detail::definite_path(target,location);
+
+            std::error_code insert_ec;
+            jsonpointer::add_if_absent(target,npath,val,insert_ec); // try insert without replace
+            if (insert_ec) // try a replace
+            {
+                std::error_code select_ec;
+                Json orig_val = jsonpointer::get(target,npath,select_ec);
+                if (select_ec) // shouldn't happen
+                {
+                    ec = jsonpatch_errc::add_failed;
+                    unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                    return;
+                }
+                std::error_code replace_ec;
+                jsonpointer::replace(target,npath,val,replace_ec);
+                if (replace_ec)
+                {
+                    ec = jsonpatch_errc::add_failed;
+                    unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                    return;
+                }
+                unwinder.stack.emplace_back(detail::op_type::replace,npath,orig_val);
+            }
+            else // insert without replace succeeded
+            {
+                unwinder.stack.emplace_back(detail::op_type::remove,npath,Json::null());
+            }
+        }
+        else if (op ==jsoncons::jsonpatch::detail::jsonpatch_names<char_type>::remove_name())
+        {
+            Json val = jsonpointer::get(target,location,local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::remove_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            jsonpointer::remove(target,location,local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::remove_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            unwinder.stack.emplace_back(detail::op_type::add, location, val);
+        }
+        else if (op ==jsoncons::jsonpatch::detail::jsonpatch_names<char_type>::replace_name())
+        {
+            Json val = jsonpointer::get(target,location,local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::replace_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            auto it_value = operation.find(detail::jsonpatch_names<char_type>::value_name());
+            if (it_value == operation.object_range().end())
+            {
+                ec = jsonpatch_errc::invalid_patch;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            jsonpointer::replace(target, location, it_value->value(), local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::replace_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            unwinder.stack.emplace_back(detail::op_type::replace,location,val);
+        }
+        else if (op ==jsoncons::jsonpatch::detail::jsonpatch_names<char_type>::move_name())
+        {
+            auto it_from = operation.find(detail::jsonpatch_names<char_type>::from_name());
+            if (it_from == operation.object_range().end())
+            {
+                ec = jsonpatch_errc::invalid_patch;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            string_type from = it_from->value().as_string();
+            auto from_pointer = json_pointer_type::parse(from, local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::move_failed;
+                unwinder.state = jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+
+            Json val = jsonpointer::get(target, from_pointer, local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::move_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            jsonpointer::remove(target, from_pointer, local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::move_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            unwinder.stack.emplace_back(detail::op_type::add, from_pointer, val);
+            // add
+            std::error_code insert_ec;
+            auto npath = jsonpatch::detail::definite_path(target,location);
+            jsonpointer::add_if_absent(target,npath,val,insert_ec); // try insert without replace
+            if (insert_ec) // try a replace
+            {
+                std::error_code select_ec;
+                Json orig_val = jsonpointer::get(target,npath,select_ec);
+                if (select_ec) // shouldn't happen
+                {
+                    ec = jsonpatch_errc::copy_failed;
+                    unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                    return;
+                }
+                std::error_code replace_ec;
+                jsonpointer::replace(target, npath, val, replace_ec);
+                if (replace_ec)
+                {
+                    ec = jsonpatch_errc::copy_failed;
+                    unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                    return;
+                }
+                unwinder.stack.emplace_back(jsoncons::jsonpatch::detail::op_type::replace,npath,orig_val);
+            }
+            else
+            {
+                unwinder.stack.emplace_back(detail::op_type::remove,npath,Json::null());
+            }
+        }
+        else if (op ==jsoncons::jsonpatch::detail::jsonpatch_names<char_type>::copy_name())
+        {
+            auto it_from = operation.find(detail::jsonpatch_names<char_type>::from_name());
+            if (it_from == operation.object_range().end())
+            {
+                ec = jsonpatch_errc::invalid_patch;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            string_type from = it_from->value().as_string();
+            Json val = jsonpointer::get(target,from,local_ec);
+            if (local_ec)
+            {
+                ec = jsonpatch_errc::copy_failed;
+                unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                return;
+            }
+            // add
+            auto npath = jsonpatch::detail::definite_path(target,location);
+            std::error_code insert_ec;
+            jsonpointer::add_if_absent(target,npath,val,insert_ec); // try insert without replace
+            if (insert_ec) // Failed, try a replace
+            {
+                std::error_code select_ec;
+                Json orig_val = jsonpointer::get(target,npath, select_ec);
+                if (select_ec) // shouldn't happen
+                {
+                    ec = jsonpatch_errc::copy_failed;
+                    unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                    return;
+                }
+                std::error_code replace_ec;
+                jsonpointer::replace(target, npath, val,replace_ec);
+                if (replace_ec)
+                {
+                    ec = jsonpatch_errc::copy_failed;
+                    unwinder.state =jsoncons::jsonpatch::detail::state_type::abort;
+                    return;
+                }
+                unwinder.stack.emplace_back(jsoncons::jsonpatch::detail::op_type::replace,npath,orig_val);
+            }
+            else
+            {
+                unwinder.stack.emplace_back(detail::op_type::remove,npath,Json::null());
+            }
+        }
+    }
+    if (unwinder.state ==jsoncons::jsonpatch::detail::state_type::begin)
+    {
+        unwinder.state =jsoncons::jsonpatch::detail::state_type::commit;
+    }
+}
+
+template <class Json>
+Json from_diff(const Json& source, const Json& target)
+{
+    std::basic_string<typename Json::char_type> path;
+    return jsoncons::jsonpatch::detail::from_diff(source, target, path);
+}
+
+template <class Json>
+void apply_patch(Json& target, const Json& patch)
+{
+    std::error_code ec;
+    apply_patch(target, patch, ec);
+    if (ec)
+    {
+        JSONCONS_THROW(jsonpatch_error(ec));
+    }
+}
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/jsonpatch/jsonpatch_error.hpp b/include/jsoncons_ext/jsonpatch/jsonpatch_error.hpp
new file mode 100644
index 0000000..33f8007
--- /dev/null
+++ b/include/jsoncons_ext/jsonpatch/jsonpatch_error.hpp
@@ -0,0 +1,121 @@
+/// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATCH_JSONPATCH_ERROR_HPP
+#define JSONCONS_JSONPATCH_JSONPATCH_ERROR_HPP
+
+#include <jsoncons/json_exception.hpp>
+#include <system_error>
+
+namespace jsoncons { namespace jsonpatch {
+
+    enum class jsonpatch_errc 
+    {
+        success = 0,
+        invalid_patch = 1,
+        test_failed,
+        add_failed,
+        remove_failed,
+        replace_failed,
+        move_failed,
+        copy_failed
+
+    };
+
+    class jsonpatch_error_category_impl
+       : public std::error_category
+    {
+    public:
+        const char* name() const noexcept override
+        {
+            return "jsoncons/jsonpatch";
+        }
+        std::string message(int ev) const override
+        {
+            switch (static_cast<jsonpatch_errc>(ev))
+            {
+                case jsonpatch_errc::invalid_patch:
+                    return "Invalid JSON Patch document";
+                case jsonpatch_errc::test_failed:
+                    return "JSON Patch test operation failed";
+                case jsonpatch_errc::add_failed:
+                    return "JSON Patch add operation failed";
+                case jsonpatch_errc::remove_failed:
+                    return "JSON Patch remove operation failed";
+                case jsonpatch_errc::replace_failed:
+                    return "JSON Patch replace operation failed";
+                case jsonpatch_errc::move_failed:
+                    return "JSON Patch move operation failed";
+                case jsonpatch_errc::copy_failed:
+                    return "JSON Patch copy operation failed";
+                default:
+                    return "Unknown JSON Patch error";
+            }
+        }
+    };
+
+    inline
+    const std::error_category& jsonpatch_error_category()
+    {
+      static jsonpatch_error_category_impl instance;
+      return instance;
+    }
+
+    inline 
+    std::error_code make_error_code(jsonpatch_errc result)
+    {
+        return std::error_code(static_cast<int>(result),jsonpatch_error_category());
+    }
+
+} // jsonpatch
+} // jsoncons
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::jsonpatch::jsonpatch_errc> : public true_type
+    {
+    };
+}
+
+namespace jsoncons { namespace jsonpatch {
+
+// allow to disable exceptions
+#if !defined(JSONCONS_NO_EXCEPTIONS)
+    #define JSONCONS_THROW(exception) throw exception
+    #define JSONCONS_RETHROW throw
+    #define JSONCONS_TRY try
+    #define JSONCONS_CATCH(exception) catch(exception)
+#else
+    #define JSONCONS_THROW(exception) std::terminate()
+    #define JSONCONS_RETHROW std::terminate()
+    #define JSONCONS_TRY if (true)
+    #define JSONCONS_CATCH(exception) if (false)
+#endif
+
+    class jsonpatch_error : public std::system_error, public virtual json_exception
+    {
+    public:
+        jsonpatch_error(const std::error_code& ec)
+            : std::system_error(ec)
+        {
+        }
+
+        jsonpatch_error(const jsonpatch_error& other) = default;
+
+        jsonpatch_error(jsonpatch_error&& other) = default;
+
+        jsonpatch_error& operator=(const jsonpatch_error& e) = default;
+        jsonpatch_error& operator=(jsonpatch_error&& e) = default;
+
+        const char* what() const noexcept override
+        {
+            return std::system_error::what();
+        }
+    };
+} // jsonpatch
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/expression.hpp b/include/jsoncons_ext/jsonpath/expression.hpp
new file mode 100644
index 0000000..f655f2d
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/expression.hpp
@@ -0,0 +1,3329 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_EXPRESSION_HPP
+#define JSONCONS_JSONPATH_EXPRESSION_HPP
+
+#include <string> // std::basic_string
+#include <vector> // std::vector
+#include <unordered_map> // std::unordered_map
+#include <unordered_set> // std::unordered_set
+#include <limits> // std::numeric_limits
+#include <set> // std::set
+#include <utility> // std::move
+#if defined(JSONCONS_HAS_STD_REGEX)
+#include <regex>
+#endif
+#include <jsoncons/json_type.hpp>
+#include <jsoncons_ext/jsonpath/json_location.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_error.hpp>
+
+namespace jsoncons { 
+namespace jsonpath {
+
+    struct reference_arg_t
+    {
+        explicit reference_arg_t() = default;
+    };
+    constexpr reference_arg_t reference_arg{};
+
+    struct const_reference_arg_t
+    {
+        explicit const_reference_arg_t() = default;
+    };
+    constexpr const_reference_arg_t const_reference_arg{};
+
+    struct literal_arg_t
+    {
+        explicit literal_arg_t() = default;
+    };
+    constexpr literal_arg_t literal_arg{};
+
+    struct end_of_expression_arg_t
+    {
+        explicit end_of_expression_arg_t() = default;
+    };
+    constexpr end_of_expression_arg_t end_of_expression_arg{};
+
+    struct separator_arg_t
+    {
+        explicit separator_arg_t() = default;
+    };
+    constexpr separator_arg_t separator_arg{};
+
+    struct lparen_arg_t
+    {
+        explicit lparen_arg_t() = default;
+    };
+    constexpr lparen_arg_t lparen_arg{};
+
+    struct rparen_arg_t
+    {
+        explicit rparen_arg_t() = default;
+    };
+    constexpr rparen_arg_t rparen_arg{};
+
+    struct begin_union_arg_t
+    {
+        explicit begin_union_arg_t() = default;
+    };
+    constexpr begin_union_arg_t begin_union_arg{};
+
+    struct end_union_arg_t
+    {
+        explicit end_union_arg_t() = default;
+    };
+    constexpr end_union_arg_t end_union_arg{};
+
+    struct begin_filter_arg_t
+    {
+        explicit begin_filter_arg_t() = default;
+    };
+    constexpr begin_filter_arg_t begin_filter_arg{};
+
+    struct end_filter_arg_t
+    {
+        explicit end_filter_arg_t() = default;
+    };
+    constexpr end_filter_arg_t end_filter_arg{};
+
+    struct begin_expression_arg_t
+    {
+        explicit begin_expression_arg_t() = default;
+    };
+    constexpr begin_expression_arg_t begin_expression_arg{};
+
+    struct end_index_expression_arg_t
+    {
+        explicit end_index_expression_arg_t() = default;
+    };
+    constexpr end_index_expression_arg_t end_index_expression_arg{};
+
+    struct end_argument_expression_arg_t
+    {
+        explicit end_argument_expression_arg_t() = default;
+    };
+    constexpr end_argument_expression_arg_t end_argument_expression_arg{};
+
+    struct current_node_arg_t
+    {
+        explicit current_node_arg_t() = default;
+    };
+    constexpr current_node_arg_t current_node_arg{};
+
+    struct root_node_arg_t
+    {
+        explicit root_node_arg_t() = default;
+    };
+    constexpr root_node_arg_t root_node_arg{};
+
+    struct end_function_arg_t
+    {
+        explicit end_function_arg_t() = default;
+    };
+    constexpr end_function_arg_t end_function_arg{};
+
+    struct argument_arg_t
+    {
+        explicit argument_arg_t() = default;
+    };
+    constexpr argument_arg_t argument_arg{};
+
+    enum class result_options {value=0, nodups=1, sort=2, path=4};
+
+    using result_type = result_options;
+
+    inline result_options operator~(result_options a)
+    {
+        return static_cast<result_options>(~static_cast<unsigned int>(a));
+    }
+
+    inline result_options operator&(result_options a, result_options b)
+    {
+        return static_cast<result_options>(static_cast<unsigned int>(a) & static_cast<unsigned int>(b));
+    }
+
+    inline result_options operator^(result_options a, result_options b)
+    {
+        return static_cast<result_options>(static_cast<unsigned int>(a) ^ static_cast<unsigned int>(b));
+    }
+
+    inline result_options operator|(result_options a, result_options b)
+    {
+        return static_cast<result_options>(static_cast<unsigned int>(a) | static_cast<unsigned int>(b));
+    }
+
+    inline result_options operator&=(result_options& a, result_options b)
+    {
+        a = a & b;
+        return a;
+    }
+
+    inline result_options operator^=(result_options& a, result_options b)
+    {
+        a = a ^ b;
+        return a;
+    }
+
+    inline result_options operator|=(result_options& a, result_options b)
+    {
+        a = a | b;
+        return a;
+    }
+
+    template <class Json>
+    class parameter;
+
+    template <class Json,class JsonReference>
+    class value_or_pointer
+    {
+    public:
+        friend class parameter<Json>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<reference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+    private:
+        bool is_value_;
+        union
+        {
+            value_type val_;
+            pointer ptr_;
+        };
+    public:
+        value_or_pointer(value_type&& val)
+            : is_value_(true), val_(std::move(val))
+        {
+        }
+
+        value_or_pointer(pointer ptr)
+            : is_value_(false), ptr_(std::move(ptr))
+        {
+        }
+
+        value_or_pointer(value_or_pointer&& other) noexcept
+            : is_value_(other.is_value_)
+        {
+            if (is_value_)
+            {
+                new(&val_)value_type(std::move(other.val_));
+            }
+            else
+            {
+                ptr_ = other.ptr_;
+            }
+        }
+
+        ~value_or_pointer() noexcept
+        {
+            if (is_value_)
+            {
+                val_.~value_type();
+            }
+        }
+
+        value_or_pointer& operator=(value_or_pointer&& other) noexcept
+        {
+            if (is_value_)
+            {
+                val_.~value_type();
+            }
+            is_value_ = other.is_value_;
+
+            if (is_value_)
+            {
+                new(&val_)value_type(std::move(other.val_));
+            }
+            else
+            {
+                ptr_ = other.ptr_;
+            }
+            return *this;
+        }
+
+        reference value() 
+        {
+            return is_value_ ? val_ : *ptr_;
+        }
+
+        pointer ptr() 
+        {
+            return is_value_ ? &val_ : ptr_;
+        }
+    };
+
+    template <class Json>
+    class parameter
+    {
+        using value_type = Json;
+        using reference = const Json&;
+        using pointer = const Json*;
+    private:
+        value_or_pointer<Json,reference> data_;
+    public:
+        template <class JsonReference>
+        parameter(value_or_pointer<Json,JsonReference>&& data) noexcept
+            : data_(nullptr)
+        {
+            data_.is_value_ = data.is_value_;
+            if (data.is_value_)
+            {
+                data_.val_ = std::move(data.val_);
+            }
+            else
+            {
+                data_.ptr_ = data.ptr_;
+            }
+        }
+
+        parameter(parameter&& other) noexcept = default;
+
+        parameter& operator=(parameter&& other) noexcept = default;
+
+        const Json& value() const
+        {
+            return data_.is_value_ ? data_.val_ : *data_.ptr_;
+        }
+    };
+
+    template <class Json>
+    class custom_function
+    {
+    public:
+        using value_type = Json;
+        using char_type = typename Json::char_type;
+        using parameter_type = parameter<Json>;
+        using function_type = std::function<value_type(jsoncons::span<const parameter_type>, std::error_code& ec)>;
+        using string_type = std::basic_string<char_type>;
+
+        string_type function_name_;
+        optional<std::size_t> arity_;
+        function_type f_;
+
+        custom_function(const string_type& function_name,
+                        const optional<std::size_t>& arity,
+                        const function_type& f)
+            : function_name_(function_name),
+              arity_(arity),
+              f_(f)
+        {
+        }
+
+        custom_function(string_type&& function_name,
+                        optional<std::size_t>&& arity,
+                        function_type&& f)
+            : function_name_(std::move(function_name)),
+              arity_(std::move(arity)),
+              f_(std::move(f))
+        {
+        }
+
+        custom_function(const custom_function&) = default;
+
+        custom_function(custom_function&&) = default;
+
+        const string_type& name() const 
+        {
+            return function_name_;
+        }
+
+        optional<std::size_t> arity() const 
+        {
+            return arity_;
+        }
+
+        const function_type& function() const 
+        {
+            return f_;
+        }
+    };
+
+    template <class Json>
+    class custom_functions
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using function_type = std::function<value_type(jsoncons::span<const parameter_type>, std::error_code& ec)>;
+        using const_iterator = typename std::vector<custom_function<Json>>::const_iterator;
+
+        std::vector<custom_function<Json>> functions_;
+    public:
+        void register_function(const string_type& name,
+                               jsoncons::optional<std::size_t> arity,
+                               const function_type& f)
+        {
+            functions_.emplace_back(name, arity, f);
+        }
+
+        const_iterator begin() const
+        {
+            return functions_.begin();
+        }
+
+        const_iterator end() const
+        {
+            return functions_.end();
+        }
+    };
+
+namespace detail {
+
+    template <class Json,class JsonReference>
+    class dynamic_resources;
+
+    template <class Json,class JsonReference>
+    struct unary_operator
+    {
+        std::size_t precedence_level_;
+        bool is_right_associative_;
+
+        unary_operator(std::size_t precedence_level,
+                       bool is_right_associative)
+            : precedence_level_(precedence_level),
+              is_right_associative_(is_right_associative)
+        {
+        }
+
+        virtual ~unary_operator() = default;
+
+        std::size_t precedence_level() const 
+        {
+            return precedence_level_;
+        }
+        bool is_right_associative() const
+        {
+            return is_right_associative_;
+        }
+
+        virtual Json evaluate(JsonReference, 
+                              std::error_code&) const = 0;
+    };
+
+    template <class Json>
+    bool is_false(const Json& val)
+    {
+        return ((val.is_array() && val.empty()) ||
+                 (val.is_object() && val.empty()) ||
+                 (val.is_string() && val.as_string_view().empty()) ||
+                 (val.is_bool() && !val.as_bool()) ||
+                 val.is_null());
+    }
+
+    template <class Json>
+    bool is_true(const Json& val)
+    {
+        return !is_false(val);
+    }
+
+    template <class Json,class JsonReference>
+    class unary_not_operator final : public unary_operator<Json,JsonReference>
+    {
+    public:
+        unary_not_operator()
+            : unary_operator<Json,JsonReference>(1, true)
+        {}
+
+        Json evaluate(JsonReference val, 
+                      std::error_code&) const override
+        {
+            return is_false(val) ? Json(true) : Json(false);
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class unary_minus_operator final : public unary_operator<Json,JsonReference>
+    {
+    public:
+        unary_minus_operator()
+            : unary_operator<Json,JsonReference>(1, true)
+        {}
+
+        Json evaluate(JsonReference val, 
+                      std::error_code&) const override
+        {
+            if (val.is_int64())
+            {
+                return Json(-val.template as<int64_t>());
+            }
+            else if (val.is_double())
+            {
+                return Json(-val.as_double());
+            }
+            else
+            {
+                return Json::null();
+            }
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class regex_operator final : public unary_operator<Json,JsonReference>
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+        std::basic_regex<char_type> pattern_;
+    public:
+        regex_operator(std::basic_regex<char_type>&& pattern)
+            : unary_operator<Json,JsonReference>(2, true),
+              pattern_(std::move(pattern))
+        {
+        }
+
+        regex_operator(regex_operator&&) = default;
+        regex_operator& operator=(regex_operator&&) = default;
+
+        Json evaluate(JsonReference val, 
+                             std::error_code&) const override
+        {
+            if (!val.is_string())
+            {
+                return Json::null();
+            }
+            return std::regex_search(val.as_string(), pattern_) ? Json(true) : Json(false);
+        }
+    };
+
+    template <class Json,class JsonReference>
+    struct binary_operator
+    {
+        std::size_t precedence_level_;
+        bool is_right_associative_;
+
+        binary_operator(std::size_t precedence_level,
+                        bool is_right_associative = false)
+            : precedence_level_(precedence_level),
+              is_right_associative_(is_right_associative)
+        {
+        }
+
+        std::size_t precedence_level() const 
+        {
+            return precedence_level_;
+        }
+        bool is_right_associative() const
+        {
+            return is_right_associative_;
+        }
+
+        virtual Json evaluate(JsonReference, 
+                             JsonReference, 
+
+                             std::error_code&) const = 0;
+
+        virtual std::string to_string(int = 0) const
+        {
+            return "binary operator";
+        }
+
+    protected:
+        ~binary_operator() = default;
+    };
+
+    // Implementations
+
+    template <class Json,class JsonReference>
+    class or_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        or_operator()
+            : binary_operator<Json,JsonReference>(9)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            if (lhs.is_null() && rhs.is_null())
+            {
+                return Json::null();
+            }
+            if (!is_false(lhs))
+            {
+                return lhs;
+            }
+            else
+            {
+                return rhs;
+            }
+        }
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                //s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("or operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class and_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        and_operator()
+            : binary_operator<Json,JsonReference>(8)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            if (is_true(lhs))
+            {
+                return rhs;
+            }
+            else
+            {
+                return lhs;
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("and operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class eq_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        eq_operator()
+            : binary_operator<Json,JsonReference>(6)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override 
+        {
+            return lhs == rhs ? Json(true) : Json(false);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("equal operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class ne_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        ne_operator()
+            : binary_operator<Json,JsonReference>(6)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override 
+        {
+            return lhs != rhs ? Json(true) : Json(false);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("not equal operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class lt_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        lt_operator()
+            : binary_operator<Json,JsonReference>(5)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override 
+        {
+            if (lhs.is_number() && rhs.is_number())
+            {
+                return lhs < rhs ? Json(true) : Json(false);
+            }
+            else if (lhs.is_string() && rhs.is_string())
+            {
+                return lhs < rhs ? Json(true) : Json(false);
+            }
+            return Json::null();
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("less than operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class lte_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        lte_operator()
+            : binary_operator<Json,JsonReference>(5)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override 
+        {
+            if (lhs.is_number() && rhs.is_number())
+            {
+                return lhs <= rhs ? Json(true) : Json(false);
+            }
+            else if (lhs.is_string() && rhs.is_string())
+            {
+                return lhs <= rhs ? Json(true) : Json(false);
+            }
+            return Json::null();
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("less than or equal operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class gt_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        gt_operator()
+            : binary_operator<Json,JsonReference>(5)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            //std::cout << "operator> lhs: " << lhs << ", rhs: " << rhs << "\n";
+
+            if (lhs.is_number() && rhs.is_number())
+            {
+                return lhs > rhs ? Json(true) : Json(false);
+            }
+            else if (lhs.is_string() && rhs.is_string())
+            {
+                return lhs > rhs ? Json(true) : Json(false);
+            }
+            return Json::null();
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("greater than operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class gte_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        gte_operator()
+            : binary_operator<Json,JsonReference>(5)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            if (lhs.is_number() && rhs.is_number())
+            {
+                return lhs >= rhs ? Json(true) : Json(false);
+            }
+            else if (lhs.is_string() && rhs.is_string())
+            {
+                return lhs >= rhs ? Json(true) : Json(false);
+            }
+            return Json::null();
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("greater than or equal operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class plus_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        plus_operator()
+            : binary_operator<Json,JsonReference>(4)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            if (!(lhs.is_number() && rhs.is_number()))
+            {
+                return Json::null();
+            }
+            else if (lhs.is_int64() && rhs.is_int64())
+            {
+                return Json(((lhs.template as<int64_t>() + rhs.template as<int64_t>())));
+            }
+            else if (lhs.is_uint64() && rhs.is_uint64())
+            {
+                return Json((lhs.template as<uint64_t>() + rhs.template as<uint64_t>()));
+            }
+            else
+            {
+                return Json((lhs.as_double() + rhs.as_double()));
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("plus operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class minus_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        minus_operator()
+            : binary_operator<Json,JsonReference>(4)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            if (!(lhs.is_number() && rhs.is_number()))
+            {
+                return Json::null();
+            }
+            else if (lhs.is_int64() && rhs.is_int64())
+            {
+                return Json(((lhs.template as<int64_t>() - rhs.template as<int64_t>())));
+            }
+            else if (lhs.is_uint64() && rhs.is_uint64())
+            {
+                return Json((lhs.template as<uint64_t>() - rhs.template as<uint64_t>()));
+            }
+            else
+            {
+                return Json((lhs.as_double() - rhs.as_double()));
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("minus operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class mult_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        mult_operator()
+            : binary_operator<Json,JsonReference>(3)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            if (!(lhs.is_number() && rhs.is_number()))
+            {
+                return Json::null();
+            }
+            else if (lhs.is_int64() && rhs.is_int64())
+            {
+                return Json(((lhs.template as<int64_t>() * rhs.template as<int64_t>())));
+            }
+            else if (lhs.is_uint64() && rhs.is_uint64())
+            {
+                return Json((lhs.template as<uint64_t>() * rhs.template as<uint64_t>()));
+            }
+            else
+            {
+                return Json((lhs.as_double() * rhs.as_double()));
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("multiply operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class div_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        div_operator()
+            : binary_operator<Json,JsonReference>(3)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            //std::cout << "operator/ lhs: " << lhs << ", rhs: " << rhs << "\n";
+
+            if (!(lhs.is_number() && rhs.is_number()))
+            {
+                return Json::null();
+            }
+            else if (lhs.is_int64() && rhs.is_int64())
+            {
+                return Json(((lhs.template as<int64_t>() / rhs.template as<int64_t>())));
+            }
+            else if (lhs.is_uint64() && rhs.is_uint64())
+            {
+                return Json((lhs.template as<uint64_t>() / rhs.template as<uint64_t>()));
+            }
+            else
+            {
+                return Json((lhs.as_double() / rhs.as_double()));
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("divide operator");
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class modulus_operator final : public binary_operator<Json,JsonReference>
+    {
+    public:
+        modulus_operator()
+            : binary_operator<Json,JsonReference>(3)
+        {
+        }
+
+        Json evaluate(JsonReference lhs, JsonReference rhs, std::error_code&) const override
+        {
+            //std::cout << "operator/ lhs: " << lhs << ", rhs: " << rhs << "\n";
+
+            if (!(lhs.is_number() && rhs.is_number()))
+            {
+                return Json::null();
+            }
+            else if (lhs.is_int64() && rhs.is_int64())
+            {
+                return Json(((lhs.template as<int64_t>() % rhs.template as<int64_t>())));
+            }
+            else if (lhs.is_uint64() && rhs.is_uint64())
+            {
+                return Json((lhs.template as<uint64_t>() % rhs.template as<uint64_t>()));
+            }
+            else
+            {
+                return Json(fmod(lhs.as_double(), rhs.as_double()));
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("modulus operator");
+            return s;
+        }
+    };
+
+    // function_base
+    template <class Json>
+    class function_base
+    {
+        jsoncons::optional<std::size_t> arg_count_;
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        function_base(jsoncons::optional<std::size_t> arg_count)
+            : arg_count_(arg_count)
+        {
+        }
+
+        virtual ~function_base() noexcept = default;
+
+        jsoncons::optional<std::size_t> arity() const
+        {
+            return arg_count_;
+        }
+
+        virtual value_type evaluate(const std::vector<parameter_type>& args, 
+                                    std::error_code& ec) const = 0;
+
+        virtual std::string to_string(int level = 0) const
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("function");
+            return s;
+        }
+    };  
+
+    template <class Json>
+    class decorator_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using string_view_type = typename Json::string_view_type;
+        using function_type = std::function<value_type(jsoncons::span<const parameter_type>, std::error_code& ec)>;
+    private:
+        function_type f_;
+    public:
+        decorator_function(jsoncons::optional<std::size_t> arity,
+            const function_type& f)
+            : function_base<Json>(arity), f_(f)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args,
+            std::error_code& ec) const override
+        {
+            return f_(args, ec);
+        }
+    };
+
+    template <class Json>
+    class contains_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using string_view_type = typename Json::string_view_type;
+
+        contains_function()
+            : function_base<Json>(2)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            auto arg1= args[1].value();
+
+            switch (arg0.type())
+            {
+                case json_type::array_value:
+                    for (auto& j : arg0.array_range())
+                    {
+                        if (j == arg1)
+                        {
+                            return value_type(true);
+                        }
+                    }
+                    return value_type(false);
+                case json_type::string_value:
+                {
+                    if (!arg1.is_string())
+                    {
+                        ec = jsonpath_errc::invalid_type;
+                        return value_type::null();
+                    }
+                    auto sv0 = arg0.template as<string_view_type>();
+                    auto sv1 = arg1.template as<string_view_type>();
+                    return sv0.find(sv1) != string_view_type::npos ? value_type(true) : value_type(false);
+                }
+                default:
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("contains function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class ends_with_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using string_view_type = typename Json::string_view_type;
+
+        ends_with_function()
+            : function_base<Json>(2)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_string())
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            auto arg1= args[1].value();
+            if (!arg1.is_string())
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            auto sv0 = arg0.template as<string_view_type>();
+            auto sv1 = arg1.template as<string_view_type>();
+
+            if (sv1.length() <= sv0.length() && sv1 == sv0.substr(sv0.length() - sv1.length()))
+            {
+                return value_type(true);
+            }
+            else
+            {
+                return value_type(false);
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("ends_with function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class starts_with_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using string_view_type = typename Json::string_view_type;
+
+        starts_with_function()
+            : function_base<Json>(2)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_string())
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            auto arg1= args[1].value();
+            if (!arg1.is_string())
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            auto sv0 = arg0.template as<string_view_type>();
+            auto sv1 = arg1.template as<string_view_type>();
+
+            if (sv1.length() <= sv0.length() && sv1 == sv0.substr(0, sv1.length()))
+            {
+                return value_type(true);
+            }
+            else
+            {
+                return value_type(false);
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("starts_with function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class sum_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        sum_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_array())
+            {
+                //std::cout << "arg: " << arg0 << "\n";
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+            //std::cout << "sum function arg: " << arg0 << "\n";
+
+            double sum = 0;
+            for (auto& j : arg0.array_range())
+            {
+                if (!j.is_number())
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+                sum += j.template as<double>();
+            }
+
+            return value_type(sum);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("sum function");
+            return s;
+        }
+    };
+
+#if defined(JSONCONS_HAS_STD_REGEX)
+
+    template <class Json>
+    class tokenize_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+
+        tokenize_function()
+            : function_base<Json>(2)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            if (!args[0].value().is_string() || !args[1].value().is_string())
+            {
+                //std::cout << "arg: " << arg0 << "\n";
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+            auto arg0 = args[0].value().template as<string_type>();
+            auto arg1 = args[1].value().template as<string_type>();
+
+            std::regex::flag_type options = std::regex_constants::ECMAScript; 
+            std::basic_regex<char_type> pieces_regex(arg1, options);
+
+            std::regex_token_iterator<typename string_type::const_iterator> rit ( arg0.begin(), arg0.end(), pieces_regex, -1);
+            std::regex_token_iterator<typename string_type::const_iterator> rend;
+
+            value_type j(json_array_arg);
+            while (rit != rend) 
+            {
+                j.emplace_back(rit->str());
+                ++rit;
+            }
+            return j;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("tokenize function");
+            return s;
+        }
+    };
+
+#endif // defined(JSONCONS_HAS_STD_REGEX)
+
+    template <class Json>
+    class ceil_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        ceil_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            switch (arg0.type())
+            {
+                case json_type::uint64_value:
+                case json_type::int64_value:
+                {
+                    return value_type(arg0.template as<double>());
+                }
+                case json_type::double_value:
+                {
+                    return value_type(std::ceil(arg0.template as<double>()));
+                }
+                default:
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("ceil function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class floor_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        floor_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            switch (arg0.type())
+            {
+                case json_type::uint64_value:
+                case json_type::int64_value:
+                {
+                    return value_type(arg0.template as<double>());
+                }
+                case json_type::double_value:
+                {
+                    return value_type(std::floor(arg0.template as<double>()));
+                }
+                default:
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("floor function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class to_number_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        to_number_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            switch (arg0.type())
+            {
+                case json_type::int64_value:
+                case json_type::uint64_value:
+                case json_type::double_value:
+                    return arg0;
+                case json_type::string_value:
+                {
+                    auto sv = arg0.as_string_view();
+                    uint64_t un{0};
+                    auto result1 = jsoncons::detail::to_integer(sv.data(), sv.length(), un);
+                    if (result1)
+                    {
+                        return value_type(un);
+                    }
+                    int64_t sn{0};
+                    auto result2 = jsoncons::detail::to_integer(sv.data(), sv.length(), sn);
+                    if (result2)
+                    {
+                        return value_type(sn);
+                    }
+                    jsoncons::detail::chars_to to_double;
+                    try
+                    {
+                        auto s = arg0.as_string();
+                        double d = to_double(s.c_str(), s.length());
+                        return value_type(d);
+                    }
+                    catch (const std::exception&)
+                    {
+                        return value_type::null();
+                    }
+                }
+                default:
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("to_number function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class prod_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        prod_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_array() || arg0.empty())
+            {
+                //std::cout << "arg: " << arg0 << "\n";
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+            double prod = 1;
+            for (auto& j : arg0.array_range())
+            {
+                if (!j.is_number())
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+                prod *= j.template as<double>();
+            }
+
+            return value_type(prod);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("prod function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class avg_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        avg_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_array())
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+            if (arg0.empty())
+            {
+                return value_type::null();
+            }
+            double sum = 0;
+            for (auto& j : arg0.array_range())
+            {
+                if (!j.is_number())
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+                sum += j.template as<double>();
+            }
+
+            return value_type(sum / static_cast<double>(arg0.size()));
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("to_string function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class min_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        min_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_array())
+            {
+                //std::cout << "arg: " << arg0 << "\n";
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+            if (arg0.empty())
+            {
+                return value_type::null();
+            }
+            bool is_number = arg0.at(0).is_number();
+            bool is_string = arg0.at(0).is_string();
+            if (!is_number && !is_string)
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            std::size_t index = 0;
+            for (std::size_t i = 1; i < arg0.size(); ++i)
+            {
+                if (!(arg0.at(i).is_number() == is_number && arg0.at(i).is_string() == is_string))
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+                if (arg0.at(i) < arg0.at(index))
+                {
+                    index = i;
+                }
+            }
+
+            return arg0.at(index);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("min function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class max_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        max_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_array())
+            {
+                //std::cout << "arg: " << arg0 << "\n";
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+            if (arg0.empty())
+            {
+                return value_type::null();
+            }
+
+            bool is_number = arg0.at(0).is_number();
+            bool is_string = arg0.at(0).is_string();
+            if (!is_number && !is_string)
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            std::size_t index = 0;
+            for (std::size_t i = 1; i < arg0.size(); ++i)
+            {
+                if (!(arg0.at(i).is_number() == is_number && arg0.at(i).is_string() == is_string))
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+                if (arg0.at(i) > arg0.at(index))
+                {
+                    index = i;
+                }
+            }
+
+            return arg0.at(index);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("max function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class abs_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+
+        abs_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            switch (arg0.type())
+            {
+                case json_type::uint64_value:
+                    return arg0;
+                case json_type::int64_value:
+                {
+                    return arg0.template as<int64_t>() >= 0 ? arg0 : value_type(std::abs(arg0.template as<int64_t>()));
+                }
+                case json_type::double_value:
+                {
+                    return arg0.template as<double>() >= 0 ? arg0 : value_type(std::abs(arg0.template as<double>()));
+                }
+                default:
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("abs function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class length_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using string_view_type = typename Json::string_view_type;
+        using parameter_type = parameter<Json>;
+
+        length_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            //std::cout << "length function arg: " << arg0 << "\n";
+
+            switch (arg0.type())
+            {
+                case json_type::object_value:
+                case json_type::array_value:
+                    return value_type(arg0.size());
+                case json_type::string_value:
+                {
+                    auto sv0 = arg0.template as<string_view_type>();
+                    auto length = unicode_traits::count_codepoints(sv0.data(), sv0.size());
+                    return value_type(length);
+                }
+                default:
+                {
+                    ec = jsonpath_errc::invalid_type;
+                    return value_type::null();
+                }
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("length function");
+            return s;
+        }
+    };
+
+    template <class Json>
+    class keys_function : public function_base<Json>
+    {
+    public:
+        using value_type = Json;
+        using parameter_type = parameter<Json>;
+        using string_view_type = typename Json::string_view_type;
+
+        keys_function()
+            : function_base<Json>(1)
+        {
+        }
+
+        value_type evaluate(const std::vector<parameter_type>& args, 
+                            std::error_code& ec) const override
+        {
+            if (args.size() != *this->arity())
+            {
+                ec = jsonpath_errc::invalid_arity;
+                return value_type::null();
+            }
+
+            auto arg0= args[0].value();
+            if (!arg0.is_object())
+            {
+                ec = jsonpath_errc::invalid_type;
+                return value_type::null();
+            }
+
+            value_type result(json_array_arg);
+            result.reserve(args.size());
+
+            for (auto& item : arg0.object_range())
+            {
+                result.emplace_back(item.key());
+            }
+            return result;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("keys function");
+            return s;
+        }
+    };
+
+    enum class jsonpath_token_kind
+    {
+        root_node,
+        current_node,
+        expression,
+        lparen,
+        rparen,
+        begin_union,
+        end_union,
+        begin_filter,
+        end_filter,
+        begin_expression,
+        end_index_expression,
+        end_argument_expression,
+        separator,
+        literal,
+        selector,
+        function,
+        end_function,
+        argument,
+        unary_operator,
+        binary_operator
+    };
+
+    inline
+    std::string to_string(jsonpath_token_kind kind)
+    {
+        switch (kind)
+        {
+            case jsonpath_token_kind::root_node:
+                return "root_node";
+            case jsonpath_token_kind::current_node:
+                return "current_node";
+            case jsonpath_token_kind::lparen:
+                return "lparen";
+            case jsonpath_token_kind::rparen:
+                return "rparen";
+            case jsonpath_token_kind::begin_union:
+                return "begin_union";
+            case jsonpath_token_kind::end_union:
+                return "end_union";
+            case jsonpath_token_kind::begin_filter:
+                return "begin_filter";
+            case jsonpath_token_kind::end_filter:
+                return "end_filter";
+            case jsonpath_token_kind::begin_expression:
+                return "begin_expression";
+            case jsonpath_token_kind::end_index_expression:
+                return "end_index_expression";
+            case jsonpath_token_kind::end_argument_expression:
+                return "end_argument_expression";
+            case jsonpath_token_kind::separator:
+                return "separator";
+            case jsonpath_token_kind::literal:
+                return "literal";
+            case jsonpath_token_kind::selector:
+                return "selector";
+            case jsonpath_token_kind::function:
+                return "function";
+            case jsonpath_token_kind::end_function:
+                return "end_function";
+            case jsonpath_token_kind::argument:
+                return "argument";
+            case jsonpath_token_kind::unary_operator:
+                return "unary_operator";
+            case jsonpath_token_kind::binary_operator:
+                return "binary_operator";
+            default:
+                return "";
+        }
+    }
+
+    template <class Json,class JsonReference>
+    struct path_value_pair
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using value_pointer = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        using json_location_node_type = json_location_node<char_type>;
+        using json_location_type = json_location<char_type>;
+        using path_pointer = const json_location_node_type*;
+
+        json_location_type path_;
+        value_pointer value_ptr_;
+
+        path_value_pair(const json_location_type& path, reference value) noexcept
+            : path_(path), value_ptr_(std::addressof(value))
+        {
+        }
+
+        path_value_pair(json_location_type&& path, value_pointer valp) noexcept
+            : path_(std::move(path)), value_ptr_(valp)
+        {
+        }
+
+        path_value_pair(const path_value_pair&) = default;
+        path_value_pair(path_value_pair&& other) = default;
+        path_value_pair& operator=(const path_value_pair&) = default;
+        path_value_pair& operator=(path_value_pair&& other) = default;
+
+        json_location_type path() const
+        {
+            return path_;
+        }
+
+        reference value() 
+        {
+            return *value_ptr_;
+        }
+    };
+ 
+    template <class Json,class JsonReference>
+    struct path_value_pair_less
+    {
+        bool operator()(const path_value_pair<Json,JsonReference>& lhs,
+                        const path_value_pair<Json,JsonReference>& rhs) const noexcept
+        {
+            return lhs.path() < rhs.path();
+        }
+    };
+
+    template <class Json,class JsonReference>
+    struct path_value_pair_equal
+    {
+        bool operator()(const path_value_pair<Json,JsonReference>& lhs,
+                        const path_value_pair<Json,JsonReference>& rhs) const noexcept
+        {
+            return lhs.path() == rhs.path();
+        }
+    };
+
+    template <class Json,class JsonReference>
+    struct path_component_value_pair
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using value_pointer = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        using json_location_node_type = json_location_node<char_type>;
+        using json_location_type = json_location<char_type>;
+        using path_pointer = const json_location_node_type*;
+    private:
+        const json_location_node_type* last_ptr_;
+        value_pointer value_ptr_;
+    public:
+        path_component_value_pair(const json_location_node_type& last, reference value) noexcept
+            : last_ptr_(std::addressof(last)), value_ptr_(std::addressof(value))
+        {
+        }
+
+        const json_location_node_type& last() const
+        {
+            return *last_ptr_;
+        }
+
+        reference value() const
+        {
+            return *value_ptr_;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class node_receiver
+    {
+    public:
+        using char_type = typename Json::char_type;
+        using reference = JsonReference;
+        using json_location_node_type = json_location_node<char_type>;
+
+        virtual ~node_receiver() noexcept = default;
+
+        virtual void add(const json_location_node_type& path_tail, 
+                         reference value) = 0;
+    };
+
+    template <class Json,class JsonReference>
+    class path_value_receiver : public node_receiver<Json,JsonReference>
+    {
+    public:
+        using reference = JsonReference;
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+        using json_location_type = json_location<char_type>;
+        using path_value_pair_type = path_value_pair<Json,JsonReference>;
+
+        std::vector<path_value_pair_type> nodes;
+
+        void add(const json_location_node_type& path_tail, 
+                 reference value) override
+        {
+            nodes.emplace_back(json_location_type(path_tail), std::addressof(value));
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class path_stem_value_receiver : public node_receiver<Json,JsonReference>
+    {
+    public:
+        using reference = JsonReference;
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+        using path_stem_value_pair_type = path_component_value_pair<Json,JsonReference>;
+
+        std::vector<path_stem_value_pair_type> nodes;
+
+        void add(const json_location_node_type& path_tail, 
+                 reference value) override
+        {
+            nodes.emplace_back(path_tail, value);
+        }
+    };
+
+    template <class Json, class JsonReference>
+    class dynamic_resources
+    {
+        using reference = JsonReference;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<reference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        using json_location_node_type = json_location_node<typename Json::char_type>;
+        using path_stem_value_pair_type = path_component_value_pair<Json,JsonReference>;
+        std::vector<std::unique_ptr<Json>> temp_json_values_;
+        std::vector<std::unique_ptr<json_location_node_type>> temp_path_node_values_;
+        std::unordered_map<std::size_t,pointer> cache_;
+    public:
+        bool is_cached(std::size_t id) const
+        {
+            return cache_.find(id) != cache_.end();
+        }
+        void add_to_cache(std::size_t id, reference val) 
+        {
+            cache_.emplace(id, std::addressof(val));
+        }
+        reference retrieve_from_cache(std::size_t id) 
+        {
+            return *cache_[id];
+        }
+
+        reference null_value()
+        {
+            static Json j{ null_type{} };
+            return j;
+        }
+
+        template <typename... Args>
+        Json* create_json(Args&& ... args)
+        {
+            auto temp = jsoncons::make_unique<Json>(std::forward<Args>(args)...);
+            Json* ptr = temp.get();
+            temp_json_values_.emplace_back(std::move(temp));
+            return ptr;
+        }
+
+        const json_location_node_type& root_path_node() const
+        {
+            static json_location_node_type root('$');
+            return root;
+        }
+
+        const json_location_node_type& current_path_node() const
+        {
+            static json_location_node_type root('@');
+            return root;
+        }
+
+        template <typename... Args>
+        const json_location_node_type* create_path_node(Args&& ... args)
+        {
+            auto temp = jsoncons::make_unique<json_location_node_type>(std::forward<Args>(args)...);
+            json_location_node_type* ptr = temp.get();
+            temp_path_node_values_.emplace_back(std::move(temp));
+            return ptr;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    struct node_less
+    {
+        bool operator()(const path_value_pair<Json,JsonReference>& a, const path_value_pair<Json,JsonReference>& b) const
+        {
+            return *(a.ptr) < *(b.ptr);
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class jsonpath_selector
+    {
+        bool is_path_;
+        std::size_t precedence_level_;
+
+    public:
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using string_view_type = jsoncons::basic_string_view<char_type, std::char_traits<char_type>>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        using path_value_pair_type = path_value_pair<Json,JsonReference>;
+        using json_location_node_type = json_location_node<char_type>;
+        using json_location_type = json_location<char_type>;
+        using node_receiver_type = node_receiver<Json,JsonReference>;
+        using selector_type = jsonpath_selector<Json,JsonReference>;
+
+        jsonpath_selector(bool is_path,
+                          std::size_t precedence_level = 0)
+            : is_path_(is_path), 
+              precedence_level_(precedence_level)
+        {
+        }
+
+        virtual ~jsonpath_selector() noexcept = default;
+
+        bool is_path() const 
+        {
+            return is_path_;
+        }
+
+        std::size_t precedence_level() const
+        {
+            return precedence_level_;
+        }
+
+        bool is_right_associative() const
+        {
+            return true;
+        }
+
+        virtual void select(dynamic_resources<Json,JsonReference>& resources,
+                            reference root,
+                            const json_location_node_type& path_tail, 
+                            reference val, 
+                            node_receiver_type& receiver,
+                            result_options options) const = 0;
+
+        virtual reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                                   reference root,
+                                   const json_location_node_type& path_tail, 
+                                   reference current, 
+                                   result_options options,
+                                   std::error_code& ec) const = 0;
+
+        virtual void append_selector(jsonpath_selector*) 
+        {
+        }
+
+        virtual std::string to_string(int = 0) const
+        {
+            return std::string();
+        }
+    };
+
+    template <class Json, class JsonReference>
+    struct static_resources
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using function_base_type = function_base<Json>;
+        using selector_type = jsonpath_selector<Json,JsonReference>;
+
+        std::vector<std::unique_ptr<selector_type>> selectors_;
+        std::vector<std::unique_ptr<Json>> temp_json_values_;
+        std::vector<std::unique_ptr<unary_operator<Json,JsonReference>>> unary_operators_;
+        std::unordered_map<string_type,std::unique_ptr<function_base_type>> custom_functions_;
+
+        static_resources()
+        {
+        }
+
+        static_resources(const custom_functions<Json>& functions)
+        {
+            for (const auto& item : functions)
+            {
+                custom_functions_.emplace(item.name(),
+                                          jsoncons::make_unique<decorator_function<Json>>(item.arity(),item.function()));
+            }
+        }
+
+        static_resources(const static_resources&) = default;
+
+        static_resources(static_resources&& other) noexcept 
+            : selectors_(std::move(other.selectors_)),
+              temp_json_values_(std::move(other.temp_json_values_)),
+              unary_operators_(std::move(other.unary_operators_)),
+              custom_functions_(std::move(other.custom_functions_))
+        {
+        }
+
+        const function_base_type* get_function(const string_type& name, std::error_code& ec) const
+        {
+            static abs_function<Json> abs_func;
+            static contains_function<Json> contains_func;
+            static starts_with_function<Json> starts_with_func;
+            static ends_with_function<Json> ends_with_func;
+            static ceil_function<Json> ceil_func;
+            static floor_function<Json> floor_func;
+            static to_number_function<Json> to_number_func;
+            static sum_function<Json> sum_func;
+            static prod_function<Json> prod_func;
+            static avg_function<Json> avg_func;
+            static min_function<Json> min_func;
+            static max_function<Json> max_func;
+            static length_function<Json> length_func;
+            static keys_function<Json> keys_func;
+#if defined(JSONCONS_HAS_STD_REGEX)
+            static tokenize_function<Json> tokenize_func;
+#endif
+
+            static std::unordered_map<string_type,const function_base_type*> functions =
+            {
+                {string_type{'a','b','s'}, &abs_func},
+                {string_type{'c','o','n','t','a','i','n','s'}, &contains_func},
+                {string_type{'s','t','a','r','t','s','_','w','i','t','h'}, &starts_with_func},
+                {string_type{'e','n','d','s','_','w','i','t','h'}, &ends_with_func},
+                {string_type{'c','e','i','l'}, &ceil_func},
+                {string_type{'f','l','o','o','r'}, &floor_func},
+                {string_type{'t','o','_','n','u','m','b','e','r'}, &to_number_func},
+                {string_type{'s','u','m'}, &sum_func},
+                {string_type{'p','r','o', 'd'}, &prod_func},
+                {string_type{'a','v','g'}, &avg_func},
+                {string_type{'m','i','n'}, &min_func},
+                {string_type{'m','a','x'}, &max_func},
+                {string_type{'l','e','n','g','t','h'}, &length_func},
+                {string_type{'k','e','y','s'}, &keys_func},
+#if defined(JSONCONS_HAS_STD_REGEX)
+                {string_type{'t','o','k','e','n','i','z','e'}, &tokenize_func},
+#endif
+                {string_type{'c','o','u','n','t'}, &length_func}
+            };
+
+            auto it = functions.find(name);
+            if (it == functions.end())
+            {
+                auto it2 = custom_functions_.find(name);
+                if (it2 == custom_functions_.end())
+                {
+                    ec = jsonpath_errc::unknown_function;
+                    return nullptr;
+                }
+                else
+                {
+                    return it2->second.get();
+                }
+            }
+            else
+            {
+                return it->second;
+            }
+        }
+
+        const unary_operator<Json,JsonReference>* get_unary_not() const
+        {
+            static unary_not_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const unary_operator<Json,JsonReference>* get_unary_minus() const
+        {
+            static unary_minus_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const unary_operator<Json,JsonReference>* get_regex_operator(std::basic_regex<char_type>&& pattern) 
+        {
+            unary_operators_.push_back(jsoncons::make_unique<regex_operator<Json,JsonReference>>(std::move(pattern)));
+            return unary_operators_.back().get();
+        }
+
+        const binary_operator<Json,JsonReference>* get_or_operator() const
+        {
+            static or_operator<Json,JsonReference> oper;
+
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_and_operator() const
+        {
+            static and_operator<Json,JsonReference> oper;
+
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_eq_operator() const
+        {
+            static eq_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_ne_operator() const
+        {
+            static ne_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_lt_operator() const
+        {
+            static lt_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_lte_operator() const
+        {
+            static lte_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_gt_operator() const
+        {
+            static gt_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_gte_operator() const
+        {
+            static gte_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_plus_operator() const
+        {
+            static plus_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_minus_operator() const
+        {
+            static minus_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_mult_operator() const
+        {
+            static mult_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_div_operator() const
+        {
+            static div_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        const binary_operator<Json,JsonReference>* get_modulus_operator() const
+        {
+            static modulus_operator<Json,JsonReference> oper;
+            return &oper;
+        }
+
+        template <typename T>
+        selector_type* new_selector(T&& val)
+        {
+            selectors_.emplace_back(jsoncons::make_unique<T>(std::forward<T>(val)));
+            return selectors_.back().get();
+        }
+
+        template <typename... Args>
+        Json* create_json(Args&& ... args)
+        {
+            auto temp = jsoncons::make_unique<Json>(std::forward<Args>(args)...);
+            Json* ptr = temp.get();
+            temp_json_values_.emplace_back(std::move(temp));
+            return ptr;
+        }
+    };
+
+    template <class Json, class JsonReference>
+    class expression_base
+    {
+    public:
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using string_view_type = jsoncons::basic_string_view<char_type, std::char_traits<char_type>>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,typename Json::const_pointer,typename Json::pointer>::type;
+        using path_value_pair_type = path_value_pair<Json,JsonReference>;
+        using json_location_node_type = json_location_node<char_type>;
+
+        virtual ~expression_base() noexcept = default;
+
+        virtual value_type evaluate(dynamic_resources<Json,JsonReference>& resources,
+                                           reference root,
+                                           //const json_location_node_type& path, 
+                                           reference val, 
+                                           result_options options,
+                                           std::error_code& ec) const = 0;
+
+        virtual std::string to_string(int level = 0) const = 0;
+    };
+
+    template <class Json,class JsonReference>
+    class token
+    {
+    public:
+        using selector_type = jsonpath_selector<Json,JsonReference>;
+        using expression_base_type = expression_base<Json,JsonReference>;
+
+        jsonpath_token_kind token_kind_;
+
+        union
+        {
+            selector_type* selector_;
+            std::unique_ptr<expression_base_type> expression_;
+            const unary_operator<Json,JsonReference>* unary_operator_;
+            const binary_operator<Json,JsonReference>* binary_operator_;
+            const function_base<Json>* function_;
+            Json value_;
+        };
+    public:
+
+        token(const unary_operator<Json,JsonReference>* expr) noexcept
+            : token_kind_(jsonpath_token_kind::unary_operator),
+              unary_operator_(expr)
+        {
+        }
+
+        token(const binary_operator<Json,JsonReference>* expr) noexcept
+            : token_kind_(jsonpath_token_kind::binary_operator),
+              binary_operator_(expr)
+        {
+        }
+
+        token(current_node_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::current_node)
+        {
+        }
+
+        token(root_node_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::root_node)
+        {
+        }
+
+        token(end_function_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::end_function)
+        {
+        }
+
+        token(separator_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::separator)
+        {
+        }
+
+        token(lparen_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::lparen)
+        {
+        }
+
+        token(rparen_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::rparen)
+        {
+        }
+
+        token(begin_union_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::begin_union)
+        {
+        }
+
+        token(end_union_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::end_union)
+        {
+        }
+
+        token(begin_filter_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::begin_filter)
+        {
+        }
+
+        token(end_filter_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::end_filter)
+        {
+        }
+
+        token(begin_expression_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::begin_expression)
+        {
+        }
+
+        token(end_index_expression_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::end_index_expression)
+        {
+        }
+
+        token(end_argument_expression_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::end_argument_expression)
+        {
+        }
+
+        token(selector_type* selector)
+            : token_kind_(jsonpath_token_kind::selector), selector_(selector)
+        {
+        }
+
+        token(std::unique_ptr<expression_base_type>&& expr)
+            : token_kind_(jsonpath_token_kind::expression)
+        {
+            new (&expression_) std::unique_ptr<expression_base_type>(std::move(expr));
+        }
+
+        token(const function_base<Json>* function) noexcept
+            : token_kind_(jsonpath_token_kind::function),
+              function_(function)
+        {
+        }
+
+        token(argument_arg_t) noexcept
+            : token_kind_(jsonpath_token_kind::argument)
+        {
+        }
+
+        token(literal_arg_t, Json&& value) noexcept
+            : token_kind_(jsonpath_token_kind::literal), value_(std::move(value))
+        {
+        }
+
+        token(token&& other) noexcept
+        {
+            construct(std::forward<token>(other));
+        }
+
+        const Json& get_value(const_reference_arg_t, dynamic_resources<Json,JsonReference>&) const
+        {
+            return value_;
+        }
+
+        Json& get_value(reference_arg_t, dynamic_resources<Json,JsonReference>& resources) const
+        {
+            return *resources.create_json(value_);
+        }
+
+        token& operator=(token&& other)
+        {
+            if (&other != this)
+            {
+                if (token_kind_ == other.token_kind_)
+                {
+                    switch (token_kind_)
+                    {
+                        case jsonpath_token_kind::selector:
+                            selector_ = other.selector_;
+                            break;
+                        case jsonpath_token_kind::expression:
+                            expression_ = std::move(other.expression_);
+                            break;
+                        case jsonpath_token_kind::unary_operator:
+                            unary_operator_ = other.unary_operator_;
+                            break;
+                        case jsonpath_token_kind::binary_operator:
+                            binary_operator_ = other.binary_operator_;
+                            break;
+                        case jsonpath_token_kind::function:
+                            function_ = other.function_;
+                            break;
+                        case jsonpath_token_kind::literal:
+                            value_ = std::move(other.value_);
+                            break;
+                        default:
+                            break;
+                    }
+                }
+                else
+                {
+                    destroy();
+                    construct(std::forward<token>(other));
+                }
+            }
+            return *this;
+        }
+
+        ~token() noexcept
+        {
+            destroy();
+        }
+
+        jsonpath_token_kind token_kind() const
+        {
+            return token_kind_;
+        }
+
+        bool is_lparen() const
+        {
+            return token_kind_ == jsonpath_token_kind::lparen; 
+        }
+
+        bool is_rparen() const
+        {
+            return token_kind_ == jsonpath_token_kind::rparen; 
+        }
+
+        bool is_current_node() const
+        {
+            return token_kind_ == jsonpath_token_kind::current_node; 
+        }
+
+        bool is_path() const
+        {
+            return token_kind_ == jsonpath_token_kind::selector && selector_->is_path(); 
+        }
+
+        bool is_operator() const
+        {
+            return token_kind_ == jsonpath_token_kind::unary_operator || 
+                   token_kind_ == jsonpath_token_kind::binary_operator; 
+        }
+
+        std::size_t precedence_level() const
+        {
+            switch(token_kind_)
+            {
+                case jsonpath_token_kind::selector:
+                    return selector_->precedence_level();
+                case jsonpath_token_kind::unary_operator:
+                    return unary_operator_->precedence_level();
+                case jsonpath_token_kind::binary_operator:
+                    return binary_operator_->precedence_level();
+                default:
+                    return 0;
+            }
+        }
+
+        jsoncons::optional<std::size_t> arity() const
+        {
+            return token_kind_ == jsonpath_token_kind::function ? function_->arity() : jsoncons::optional<std::size_t>();
+        }
+
+        bool is_right_associative() const
+        {
+            switch(token_kind_)
+            {
+                case jsonpath_token_kind::selector:
+                    return selector_->is_right_associative();
+                case jsonpath_token_kind::unary_operator:
+                    return unary_operator_->is_right_associative();
+                case jsonpath_token_kind::binary_operator:
+                    return binary_operator_->is_right_associative();
+                default:
+                    return false;
+            }
+        }
+
+        void construct(token&& other)
+        {
+            token_kind_ = other.token_kind_;
+            switch (token_kind_)
+            {
+                case jsonpath_token_kind::selector:
+                    selector_ = other.selector_;
+                    break;
+                case jsonpath_token_kind::expression:
+                    new (&expression_) std::unique_ptr<expression_base_type>(std::move(other.expression_));
+                    break;
+                case jsonpath_token_kind::unary_operator:
+                    unary_operator_ = other.unary_operator_;
+                    break;
+                case jsonpath_token_kind::binary_operator:
+                    binary_operator_ = other.binary_operator_;
+                    break;
+                case jsonpath_token_kind::function:
+                    function_ = other.function_;
+                    break;
+                case jsonpath_token_kind::literal:
+                    new (&value_) Json(std::move(other.value_));
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        void destroy() noexcept 
+        {
+            switch(token_kind_)
+            {
+                case jsonpath_token_kind::expression:
+                    expression_.~unique_ptr();
+                    break;
+                case jsonpath_token_kind::literal:
+                    value_.~Json();
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        std::string to_string(int level = 0) const
+        {
+            std::string s;
+            switch (token_kind_)
+            {
+                case jsonpath_token_kind::root_node:
+                    if (level > 0)
+                    {
+                        s.append("\n");
+                        s.append(level*2, ' ');
+                    }
+                    s.append("root node");
+                    break;
+                case jsonpath_token_kind::current_node:
+                    if (level > 0)
+                    {
+                        s.append("\n");
+                        s.append(level*2, ' ');
+                    }
+                    s.append("current node");
+                    break;
+                case jsonpath_token_kind::argument:
+                    if (level > 0)
+                    {
+                        s.append("\n");
+                        s.append(level*2, ' ');
+                    }
+                    s.append("argument");
+                    break;
+                case jsonpath_token_kind::selector:
+                    s.append(selector_->to_string(level));
+                    break;
+                case jsonpath_token_kind::expression:
+                    s.append(expression_->to_string(level));
+                    break;
+                case jsonpath_token_kind::literal:
+                {
+                    if (level > 0)
+                    {
+                        s.append("\n");
+                        s.append(level*2, ' ');
+                    }
+                    auto sbuf = value_.to_string();
+                    unicode_traits::convert(sbuf.data(), sbuf.size(), s);
+                    break;
+                }
+                case jsonpath_token_kind::binary_operator:
+                    s.append(binary_operator_->to_string(level));
+                    break;
+                case jsonpath_token_kind::function:
+                    s.append(function_->to_string(level));
+                    break;
+                default:
+                    if (level > 0)
+                    {
+                        s.append("\n");
+                        s.append(level*2, ' ');
+                    }
+                    s.append("token kind: ");
+                    s.append(jsoncons::jsonpath::detail::to_string(token_kind_));
+                    break;
+            }
+            //s.append("\n");
+            return s;
+        }
+    };
+
+    template <class Callback, class Json,class JsonReference>
+    class callback_receiver : public node_receiver<Json,JsonReference>
+    {
+        Callback& callback_;
+    public:
+        using reference = JsonReference;
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+        using json_location_type = json_location<char_type>;
+
+        callback_receiver(Callback& callback)
+            : callback_(callback)
+        {
+        }
+
+        void add(const json_location_node_type& path_tail, 
+                 reference value) override
+        {
+            callback_(json_location_type(path_tail), value);
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class path_expression
+    {
+    public:
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using string_view_type = typename Json::string_view_type;
+        using path_value_pair_type = path_value_pair<Json,JsonReference>;
+        using path_value_pair_less_type = path_value_pair_less<Json,JsonReference>;
+        using path_value_pair_equal_type = path_value_pair_equal<Json,JsonReference>;
+        using value_type = Json;
+        using reference = typename path_value_pair_type::reference;
+        using pointer = typename path_value_pair_type::value_pointer;
+        using token_type = token<Json,JsonReference>;
+        using reference_arg_type = typename std::conditional<std::is_const<typename std::remove_reference<JsonReference>::type>::value,
+            const_reference_arg_t,reference_arg_t>::type;
+        using json_location_node_type = json_location_node<char_type>;
+        using json_location_type = json_location<char_type>;
+        using selector_type = jsonpath_selector<Json,JsonReference>;
+    private:
+        selector_type* selector_;
+        result_options required_options_;
+    public:
+
+        path_expression()
+            : required_options_()
+        {
+        }
+
+        path_expression(path_expression&& expr) = default;
+
+        path_expression(selector_type* selector, bool paths_required)
+            : selector_(selector), required_options_()
+        {
+            if (paths_required)
+            {
+                required_options_ |= result_options::path;
+            }
+        }
+
+        path_expression& operator=(path_expression&& expr) = default;
+
+        Json evaluate(dynamic_resources<Json,JsonReference>& resources, 
+                      reference root,
+                      const json_location_node_type& path, 
+                      reference instance,
+                      result_options options) const
+        {
+            Json result(json_array_arg);
+
+            if ((options & result_options::path) == result_options::path)
+            {
+                auto callback = [&result](const json_location_type& path, reference)
+                {
+                    result.emplace_back(path.to_string());
+                };
+                evaluate(resources, root, path, instance, callback, options);
+            }
+            else
+            {
+                auto callback = [&result](const json_location_type&, reference val)
+                {
+                    result.push_back(val);
+                };
+                evaluate(resources, root, path, instance, callback, options);
+            }
+
+            return result;
+        }
+
+        template <class Callback>
+        typename std::enable_if<type_traits::is_binary_function_object<Callback,const json_location_type&,reference>::value,void>::type
+        evaluate(dynamic_resources<Json,JsonReference>& resources, 
+                 reference root,
+                 const json_location_node_type& path, 
+                 reference current, 
+                 Callback callback,
+                 result_options options) const
+        {
+            std::error_code ec;
+
+            options |= required_options_;
+
+            const result_options require_more = result_options::nodups | result_options::sort;
+
+            if ((options & require_more) != result_options())
+            {
+                path_value_receiver<Json,JsonReference> receiver;
+                selector_->select(resources, root, path, current, receiver, options);
+
+                if (receiver.nodes.size() > 1 && (options & result_options::sort) == result_options::sort)
+                {
+                    std::sort(receiver.nodes.begin(), receiver.nodes.end(), path_value_pair_less_type());
+                }
+
+                if (receiver.nodes.size() > 1 && (options & result_options::nodups) == result_options::nodups)
+                {
+                    if ((options & result_options::sort) == result_options::sort)
+                    {
+                        auto last = std::unique(receiver.nodes.begin(),receiver.nodes.end(),path_value_pair_equal_type());
+                        receiver.nodes.erase(last,receiver.nodes.end());
+                        for (auto& node : receiver.nodes)
+                        {
+                            callback(node.path(), node.value());
+                        }
+                    }
+                    else
+                    {
+                        std::vector<path_value_pair_type> index(receiver.nodes);
+                        std::sort(index.begin(), index.end(), path_value_pair_less_type());
+                        auto last = std::unique(index.begin(),index.end(),path_value_pair_equal_type());
+                        index.erase(last,index.end());
+
+                        std::vector<path_value_pair_type> temp2;
+                        temp2.reserve(index.size());
+                        for (auto&& node : receiver.nodes)
+                        {
+                            auto it = std::lower_bound(index.begin(),index.end(),node, path_value_pair_less_type());
+                            if (it != index.end() && it->path() == node.path()) 
+                            {
+                                temp2.emplace_back(std::move(node));
+                                index.erase(it);
+                            }
+                        }
+                        for (auto& node : temp2)
+                        {
+                            callback(node.path(), node.value());
+                        }
+                    }
+                }
+                else
+                {
+                    for (auto& node : receiver.nodes)
+                    {
+                        callback(node.path(), node.value());
+                    }
+                }
+            }
+            else
+            {
+                callback_receiver<Callback,Json,JsonReference> receiver(callback);
+                selector_->select(resources, root, path, current, receiver, options);
+            }
+        }
+
+        std::string to_string(int level) const
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("expression ");
+            s.append(selector_->to_string(level+1));
+
+            return s;
+
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class expression : public expression_base<Json,JsonReference>
+    {
+    public:
+        using path_value_pair_type = path_value_pair<Json,JsonReference>;
+        using value_type = Json;
+        using reference = typename path_value_pair_type::reference;
+        using pointer = typename path_value_pair_type::value_pointer;
+        using const_pointer = const value_type*;
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using string_view_type = typename Json::string_view_type;
+        using path_value_pair_less_type = path_value_pair_less<Json,reference>;
+        using path_value_pair_equal_type = path_value_pair_equal<Json,reference>;
+        using parameter_type = parameter<Json>;
+        using token_type = token<Json,reference>;
+        using reference_arg_type = typename std::conditional<std::is_const<typename std::remove_reference<reference>::type>::value,
+            const_reference_arg_t,reference_arg_t>::type;
+        using json_location_node_type = json_location_node<char_type>;
+        using stack_item_type = value_or_pointer<Json,JsonReference>;
+    private:
+        std::vector<token_type> token_list_;
+    public:
+
+        expression()
+        {
+        }
+
+        expression(expression&& expr)
+            : token_list_(std::move(expr.token_list_))
+        {
+        }
+
+        expression(std::vector<token_type>&& token_stack)
+            : token_list_(std::move(token_stack))
+        {
+        }
+
+        expression& operator=(expression&& expr) = default;
+
+        value_type evaluate(dynamic_resources<Json,reference>& resources, 
+                                   reference root,
+                                   reference current,
+                                   result_options options,
+                                   std::error_code& ec) const override
+        {
+            std::vector<stack_item_type> stack;
+            std::vector<parameter_type> arg_stack;
+
+            //std::cout << "EVALUATE TOKENS\n";
+            //for (auto& tok : token_list_)
+            //{
+            //    std::cout << tok.to_string() << "\n";
+            //}
+            //std::cout << "\n";
+
+            if (!token_list_.empty())
+            {
+                for (auto& tok : token_list_)
+                {
+                    //std::cout << "Token: " << tok.to_string() << "\n";
+                    switch (tok.token_kind())
+                    { 
+                        case jsonpath_token_kind::literal:
+                        {
+                            stack.emplace_back(std::addressof(tok.get_value(reference_arg_type(), resources)));
+                            break;
+                        }
+                        case jsonpath_token_kind::unary_operator:
+                        {
+                            JSONCONS_ASSERT(stack.size() >= 1);
+                            auto item = std::move(stack.back());
+                            stack.pop_back();
+
+                            auto val = tok.unary_operator_->evaluate(item.value(), ec);
+                            stack.emplace_back(std::move(val));
+                            break;
+                        }
+                        case jsonpath_token_kind::binary_operator:
+                        {
+                            //std::cout << "binary operator: " << stack.size() << "\n";
+                            JSONCONS_ASSERT(stack.size() >= 2);
+                            auto rhs = std::move(stack.back());
+                            //std::cout << "rhs: " << *rhs << "\n";
+                            stack.pop_back();
+                            auto lhs = std::move(stack.back());
+                            //std::cout << "lhs: " << *lhs << "\n";
+                            stack.pop_back();
+
+                            auto val = tok.binary_operator_->evaluate(lhs.value(), rhs.value(), ec);
+                            //std::cout << "Evaluate binary expression: " << r << "\n";
+                            stack.emplace_back(std::move(val));
+                            break;
+                        }
+                        case jsonpath_token_kind::root_node:
+                            //std::cout << "root: " << root << "\n";
+                            stack.emplace_back(std::addressof(root));
+                            break;
+                        case jsonpath_token_kind::current_node:
+                            //std::cout << "current: " << current << "\n";
+                            stack.emplace_back(std::addressof(current));
+                            break;
+                        case jsonpath_token_kind::argument:
+                            JSONCONS_ASSERT(!stack.empty());
+                            //std::cout << "argument stack items " << stack.size() << "\n";
+                            //for (auto& item : stack)
+                            //{
+                            //    std::cout << *item.to_pointer(resources) << "\n";
+                            //}
+                            //std::cout << "\n";
+                            arg_stack.emplace_back(std::move(stack.back()));
+                            //for (auto& item : arg_stack)
+                            //{
+                            //    std::cout << *item << "\n";
+                            //}
+                            //std::cout << "\n";
+                            stack.pop_back();
+                            break;
+                        case jsonpath_token_kind::function:
+                        {
+                            if (tok.function_->arity() && *(tok.function_->arity()) != arg_stack.size())
+                            {
+                                ec = jsonpath_errc::invalid_arity;
+                                return Json::null();
+                            }
+                            //std::cout << "function arg stack:\n";
+                            //for (auto& item : arg_stack)
+                            //{
+                            //    std::cout << *item << "\n";
+                            //}
+                            //std::cout << "\n";
+
+                            value_type val = tok.function_->evaluate(arg_stack, ec);
+                            if (ec)
+                            {
+                                return Json::null();
+                            }
+                            //std::cout << "function result: " << val << "\n";
+                            arg_stack.clear();
+                            stack.emplace_back(std::move(val));
+                            break;
+                        }
+                        case jsonpath_token_kind::expression:
+                        {
+                            value_type val = tok.expression_->evaluate(resources, root, current, options, ec);
+                            stack.emplace_back(std::move(val));
+                            break;
+                        }
+                        case jsonpath_token_kind::selector:
+                        {
+                            JSONCONS_ASSERT(!stack.empty());
+                            auto item = std::move(stack.back());
+                            //for (auto& item : stack)
+                            //{
+                                //std::cout << "selector stack input:\n";
+                                //switch (item.tag)
+                                //{
+                                //    case node_set_tag::single:
+                                //        std::cout << "single: " << *(item.node.ptr) << "\n";
+                                //        break;
+                                //    case node_set_tag::multi:
+                                //        for (auto& node : stack.back().ptr().nodes)
+                                //        {
+                                //            std::cout << "multi: " << *node.ptr << "\n";
+                                //        }
+                                //        break;
+                                //    default:
+                                //        break;
+                            //}
+                            //std::cout << "\n";
+                            //}
+                            //std::cout << "selector item: " << *ptr << "\n";
+
+                            reference val = tok.selector_->evaluate(resources, root, resources.current_path_node(), item.value(), options, ec);
+
+                            stack.pop_back();
+                            stack.emplace_back(stack_item_type(std::addressof(val)));
+                            break;
+                        }
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            //if (stack.size() != 1)
+            //{
+            //    std::cout << "Stack size: " << stack.size() << "\n";
+            //}
+            return stack.empty() ? Json::null() : stack.back().value();
+        }
+ 
+        std::string to_string(int level) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("expression ");
+            for (const auto& item : token_list_)
+            {
+                s.append(item.to_string(level+1));
+            }
+
+            return s;
+
+        }
+    private:
+    };
+
+} // namespace detail
+} // namespace jsonpath
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONPATH_JSONPATH_EXPRESSION_HPP
diff --git a/include/jsoncons_ext/jsonpath/flatten.hpp b/include/jsoncons_ext/jsonpath/flatten.hpp
new file mode 100644
index 0000000..938391f
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/flatten.hpp
@@ -0,0 +1,432 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_FLATTEN_HPP
+#define JSONCONS_JSONPATH_FLATTEN_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::is_const
+#include <limits> // std::numeric_limits
+#include <utility> // std::move
+#include <algorithm> // std::copy
+#include <iterator> // std::back_inserter
+#include <jsoncons_ext/jsonpath/jsonpath.hpp>
+
+namespace jsoncons { namespace jsonpath {
+
+    template <class CharT, class Sink>
+    std::size_t escape_string(const CharT* s, std::size_t length,
+                              Sink& sink)
+    {
+        std::size_t count = 0;
+        const CharT* begin = s;
+        const CharT* end = s + length;
+        for (const CharT* it = begin; it != end; ++it)
+        {
+            CharT c = *it;
+            switch (c)
+            {
+                case '\\':
+                    sink.push_back('\\');
+                    sink.push_back('\\');
+                    count += 2;
+                    break;
+                case '\'':
+                    sink.push_back('\\');
+                    sink.push_back('\'');
+                    count += 2;
+                    break;
+                case '\b':
+                    sink.push_back('\\');
+                    sink.push_back('b');
+                    count += 2;
+                    break;
+                case '\f':
+                    sink.push_back('\\');
+                    sink.push_back('f');
+                    count += 2;
+                    break;
+                case '\n':
+                    sink.push_back('\\');
+                    sink.push_back('n');
+                    count += 2;
+                    break;
+                case '\r':
+                    sink.push_back('\\');
+                    sink.push_back('r');
+                    count += 2;
+                    break;
+                case '\t':
+                    sink.push_back('\\');
+                    sink.push_back('t');
+                    count += 2;
+                    break;
+                default:
+                    sink.push_back(c);
+                    ++count;
+                    break;
+            }
+        }
+        return count;
+    }
+
+    template<class Json>
+    void flatten_(const std::basic_string<typename Json::char_type>& parent_key,
+                  const Json& parent_value,
+                  Json& result)
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+
+        switch (parent_value.type())
+        {
+            case json_type::array_value:
+            {
+                if (parent_value.empty())
+                {
+                    result.try_emplace(parent_key, parent_value);
+                }
+                else
+                {
+                    for (std::size_t i = 0; i < parent_value.size(); ++i)
+                    {
+                        string_type key(parent_key);
+                        key.push_back('[');
+                        jsoncons::detail::from_integer(i,key);
+                        key.push_back(']');
+                        flatten_(key, parent_value.at(i), result);
+                    }
+                }
+                break;
+            }
+
+            case json_type::object_value:
+            {
+                if (parent_value.empty())
+                {
+                    result.try_emplace(parent_key, Json());
+                }
+                else
+                {
+                    for (const auto& item : parent_value.object_range())
+                    {
+                        string_type key(parent_key);
+                        key.push_back('[');
+                        key.push_back('\'');
+                        escape_string(item.key().data(), item.key().length(), key);
+                        key.push_back('\'');
+                        key.push_back(']');
+                        flatten_(key, item.value(), result);
+                    }
+                }
+                break;
+            }
+
+            default:
+            {
+                result[parent_key] = parent_value;
+                break;
+            }
+        }
+    }
+
+    template<class Json>
+    Json flatten(const Json& value)
+    {
+        Json result;
+        std::basic_string<typename Json::char_type> parent_key = {'$'};
+        flatten_(parent_key, value, result);
+        return result;
+    }
+
+    enum class unflatten_state 
+    {
+        start,
+        expect_lbracket,
+        lbracket,
+        single_quoted_name_state,
+        double_quoted_name_state,
+        index_state,
+        expect_rbracket,
+        double_quoted_string_escape_char,
+        single_quoted_string_escape_char
+    };
+
+    template<class Json>
+    Json unflatten(const Json& value)
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+
+        if (JSONCONS_UNLIKELY(!value.is_object()))
+        {
+            JSONCONS_THROW(jsonpath_error(jsonpath_errc::argument_to_unflatten_invalid));
+        }
+
+        Json result;
+
+        for (const auto& item : value.object_range())
+        {
+            Json* part = &result;
+            string_type buffer;
+            unflatten_state state = unflatten_state::start;
+
+            auto it = item.key().begin();
+            auto last = item.key().end();
+
+            for (; it != last; ++it)
+            {
+                switch (state)
+                {
+                    case unflatten_state::start:
+                    {
+                        switch (*it)
+                        {
+                            case '$':
+                                state = unflatten_state::expect_lbracket;
+                                break;
+                            default:
+                                break;
+                        }
+                        break;
+                    }
+                    case unflatten_state::expect_lbracket:
+                    {
+                        switch (*it)
+                        {
+                            case '[':
+                                state = unflatten_state::lbracket;
+                                break;
+                            default:
+                                JSONCONS_THROW(jsonpath_error(jsonpath_errc::invalid_flattened_key));
+                                break;
+                        }
+                        break;
+                    }
+                    case unflatten_state::lbracket:
+                    {
+                        switch (*it)
+                        {
+                            case '\'':
+                                state = unflatten_state::single_quoted_name_state;
+                                break;
+                            case '\"':
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                buffer.push_back(*it);
+                                state = unflatten_state::index_state;
+                                break;
+                            default:
+                                JSONCONS_THROW(jsonpath_error(jsonpath_errc::invalid_flattened_key));
+                                break;
+                        }
+                        break;
+                    }
+                    case unflatten_state::single_quoted_name_state:
+                    {
+                        switch (*it)
+                        {
+                            case '\'':
+                                if (it != last-2)
+                                {
+                                    auto res = part->try_emplace(buffer,Json());
+                                    part = &(res.first->value());
+                                }
+                                else
+                                {
+                                    auto res = part->try_emplace(buffer,item.value());
+                                    part = &(res.first->value());
+                                }
+                                buffer.clear();
+                                state = unflatten_state::expect_rbracket;
+                                break;
+                            case '\\':
+                                state = unflatten_state::single_quoted_string_escape_char;
+                                break;
+                            default:
+                                buffer.push_back(*it);
+                                break;
+                        }
+                        break;
+                    }
+                    case unflatten_state::double_quoted_name_state:
+                    {
+                        switch (*it)
+                        {
+                            case '\"':
+                                if (it != last-2)
+                                {
+                                    auto res = part->try_emplace(buffer,Json());
+                                    part = &(res.first->value());
+                                }
+                                else
+                                {
+                                    auto res = part->try_emplace(buffer,item.value());
+                                    part = &(res.first->value());
+                                }
+                                buffer.clear();
+                                state = unflatten_state::expect_rbracket;
+                                break;
+                            case '\\':
+                                state = unflatten_state::double_quoted_string_escape_char;
+                                break;
+                            default:
+                                buffer.push_back(*it);
+                                break;
+                        }
+                        break;
+                    }
+                    case unflatten_state::double_quoted_string_escape_char:
+                        switch (*it)
+                        {
+                            case '\"':
+                                buffer.push_back('\"');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case '\\': 
+                                buffer.push_back('\\');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case '/':
+                                buffer.push_back('/');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'b':
+                                buffer.push_back('\b');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'f':
+                                buffer.push_back('\f');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'n':
+                                buffer.push_back('\n');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'r':
+                                buffer.push_back('\r');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 't':
+                                buffer.push_back('\t');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            default:
+                                break;
+                        }
+                        break;
+                    case unflatten_state::single_quoted_string_escape_char:
+                        switch (*it)
+                        {
+                            case '\'':
+                                buffer.push_back('\'');
+                                state = unflatten_state::single_quoted_name_state;
+                                break;
+                            case '\\': 
+                                buffer.push_back('\\');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case '/':
+                                buffer.push_back('/');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'b':
+                                buffer.push_back('\b');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'f':
+                                buffer.push_back('\f');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'n':
+                                buffer.push_back('\n');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 'r':
+                                buffer.push_back('\r');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            case 't':
+                                buffer.push_back('\t');
+                                state = unflatten_state::double_quoted_name_state;
+                                break;
+                            default:
+                                break;
+                        }
+                        break;
+                    case unflatten_state::index_state:
+                    {
+                        switch (*it)
+                        {
+                            case ']':
+                            {
+                                std::size_t n{0};
+                                auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                                if (r)
+                                {
+                                    if (!part->is_array())
+                                    {
+                                        *part = Json(json_array_arg);
+                                    }
+                                    if (it != last-1)
+                                    {
+                                        if (n+1 > part->size())
+                                        {
+                                            Json& ref = part->emplace_back();
+                                            part = std::addressof(ref);
+                                        }
+                                        else
+                                        {
+                                            part = &part->at(n);
+                                        }
+                                    }
+                                    else
+                                    {
+                                        Json& ref = part->emplace_back(item.value());
+                                        part = std::addressof(ref);
+                                    }
+                                }
+                                buffer.clear();
+                                state = unflatten_state::expect_lbracket;
+                                break;
+                            }
+                            case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                buffer.push_back(*it);
+                                break;
+                            default:
+                                JSONCONS_THROW(jsonpath_error(jsonpath_errc::invalid_flattened_key));
+                                break;
+                        }
+                        break;
+                    }
+                    case unflatten_state::expect_rbracket:
+                    {
+                        switch (*it)
+                        {
+                            case ']':
+                                state = unflatten_state::expect_lbracket;
+                                break;
+                            default:
+                                JSONCONS_THROW(jsonpath_error(jsonpath_errc::invalid_flattened_key));
+                                break;
+                        }
+                        break;
+                    }
+                    default:
+                        JSONCONS_UNREACHABLE();
+                        break;
+                }
+            }
+        }
+
+        return result;
+    }
+}}
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/json_location.hpp b/include/jsoncons_ext/jsonpath/json_location.hpp
new file mode 100644
index 0000000..9105608
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/json_location.hpp
@@ -0,0 +1,445 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSON_LOCATION_HPP
+#define JSONCONS_JSONPATH_JSON_LOCATION_HPP
+
+#include <string>
+#include <vector>
+#include <functional>
+#include <algorithm> // std::reverse
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/detail/write_number.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_error.hpp>
+#include <jsoncons/json_type.hpp>
+
+namespace jsoncons { 
+namespace jsonpath {
+
+    template <class CharT>
+    class json_location; 
+
+    enum class json_location_node_kind { root, index, name };
+
+    template <class CharT>
+    class json_location_node 
+    {
+        friend class json_location<CharT>;
+    public:
+        using char_type = CharT;
+        using string_type = std::basic_string<CharT>;
+    private:
+
+        const json_location_node* parent_;
+        json_location_node_kind node_kind_;
+        string_type name_;
+        std::size_t index_;
+    public:
+        json_location_node(char_type c)
+            : parent_(nullptr), node_kind_(json_location_node_kind::root), index_(0)
+        {
+            name_.push_back(c);
+        }
+
+        json_location_node(const json_location_node* parent, const string_type& name)
+            : parent_(parent), node_kind_(json_location_node_kind::name), name_(name), index_(0)
+        {
+        }
+
+        json_location_node(const json_location_node* parent, std::size_t index)
+            : parent_(parent), node_kind_(json_location_node_kind::index), index_(index)
+        {
+        }
+
+        const json_location_node* parent() const { return parent_;}
+
+        json_location_node_kind node_kind() const
+        {
+            return node_kind_;
+        }
+
+        const string_type& name() const
+        {
+            return name_;
+        }
+
+        std::size_t index() const 
+        {
+            return index_;
+        }
+
+        void swap(json_location_node& node)
+        {
+            std::swap(parent_, node.parent_);
+            std::swap(node_kind_, node.node_kind_);
+            std::swap(name_, node.name_);
+            std::swap(index_, node.index_);
+        }
+
+    private:
+
+        std::size_t node_hash() const
+        {
+            std::size_t h = node_kind_ == json_location_node_kind::index ? std::hash<std::size_t>{}(index_) : std::hash<string_type>{}(name_);
+
+            return h;
+        }
+
+        int compare_node(const json_location_node& other) const
+        {
+            int diff = 0;
+            if (node_kind_ != other.node_kind_)
+            {
+                diff = static_cast<int>(node_kind_) - static_cast<int>(other.node_kind_);
+            }
+            else
+            {
+                switch (node_kind_)
+                {
+                    case json_location_node_kind::root:
+                        diff = name_.compare(other.name_);
+                        break;
+                    case json_location_node_kind::index:
+                        diff = index_ < other.index_ ? -1 : index_ > other.index_ ? 1 : 0;
+                        break;
+                    case json_location_node_kind::name:
+                        diff = name_.compare(other.name_);
+                        break;
+                }
+            }
+            return diff;
+        }
+    };
+
+    namespace detail {
+
+        template <class Iterator>
+        class json_location_iterator
+        { 
+            Iterator it_; 
+
+        public:
+            using iterator_category = std::random_access_iterator_tag;
+
+            using value_type = typename std::remove_pointer<typename std::iterator_traits<Iterator>::value_type>::type;
+            using difference_type = typename std::iterator_traits<Iterator>::difference_type;
+            using pointer = const value_type*;
+            using reference = const value_type&;
+
+            json_location_iterator() : it_()
+            { 
+            }
+
+            explicit json_location_iterator(Iterator ptr) : it_(ptr)
+            {
+            }
+
+            json_location_iterator(const json_location_iterator&) = default;
+            json_location_iterator(json_location_iterator&&) = default;
+            json_location_iterator& operator=(const json_location_iterator&) = default;
+            json_location_iterator& operator=(json_location_iterator&&) = default;
+
+            template <class Iter,
+                      class=typename std::enable_if<!std::is_same<Iter,Iterator>::value && std::is_convertible<Iter,Iterator>::value>::type>
+            json_location_iterator(const json_location_iterator<Iter>& other)
+                : it_(other.it_)
+            {
+            }
+
+            operator Iterator() const
+            { 
+                return it_; 
+            }
+
+            reference operator*() const 
+            {
+                return *(*it_);
+            }
+
+            pointer operator->() const 
+            {
+                return (*it_);
+            }
+
+            json_location_iterator& operator++() 
+            {
+                ++it_;
+                return *this;
+            }
+
+            json_location_iterator operator++(int) 
+            {
+                json_location_iterator temp = *this;
+                ++*this;
+                return temp;
+            }
+
+            json_location_iterator& operator--() 
+            {
+                --it_;
+                return *this;
+            }
+
+            json_location_iterator operator--(int) 
+            {
+                json_location_iterator temp = *this;
+                --*this;
+                return temp;
+            }
+
+            json_location_iterator& operator+=(const difference_type offset) 
+            {
+                it_ += offset;
+                return *this;
+            }
+
+            json_location_iterator operator+(const difference_type offset) const 
+            {
+                json_location_iterator temp = *this;
+                return temp += offset;
+            }
+
+            json_location_iterator& operator-=(const difference_type offset) 
+            {
+                return *this += -offset;
+            }
+
+            json_location_iterator operator-(const difference_type offset) const 
+            {
+                json_location_iterator temp = *this;
+                return temp -= offset;
+            }
+
+            difference_type operator-(const json_location_iterator& rhs) const noexcept
+            {
+                return it_ - rhs.it_;
+            }
+
+            reference operator[](const difference_type offset) const noexcept
+            {
+                return *(*(*this + offset));
+            }
+
+            bool operator==(const json_location_iterator& rhs) const noexcept
+            {
+                return it_ == rhs.it_;
+            }
+
+            bool operator!=(const json_location_iterator& rhs) const noexcept
+            {
+                return !(*this == rhs);
+            }
+
+            bool operator<(const json_location_iterator& rhs) const noexcept
+            {
+                return it_ < rhs.it_;
+            }
+
+            bool operator>(const json_location_iterator& rhs) const noexcept
+            {
+                return rhs < *this;
+            }
+
+            bool operator<=(const json_location_iterator& rhs) const noexcept
+            {
+                return !(rhs < *this);
+            }
+
+            bool operator>=(const json_location_iterator& rhs) const noexcept
+            {
+                return !(*this < rhs);
+            }
+
+            inline 
+            friend json_location_iterator<Iterator> operator+(
+                difference_type offset, json_location_iterator<Iterator> next) 
+            {
+                return next += offset;
+            }
+        };
+
+    } // namespace detail
+
+    template <class CharT>
+    class json_location
+    {
+    public:
+        using char_type = CharT;
+        using string_type = std::basic_string<CharT>;
+        using json_location_node_type = json_location_node<CharT>;
+    private:
+        std::vector<const json_location_node_type*> nodes_;
+    public:
+        using iterator = typename detail::json_location_iterator<typename std::vector<const json_location_node_type*>::iterator>;
+        using const_iterator = typename detail::json_location_iterator<typename std::vector<const json_location_node_type*>::const_iterator>;
+
+        json_location(const json_location_node_type& node)
+        {
+            const json_location_node_type* p = std::addressof(node);
+            do
+            {
+                nodes_.push_back(p);
+                p = p->parent_;
+            }
+            while (p != nullptr);
+
+            std::reverse(nodes_.begin(), nodes_.end());
+        }
+
+        iterator begin()
+        {
+            return iterator(nodes_.begin());
+        }
+
+        iterator end()
+        {
+            return iterator(nodes_.end());
+        }
+
+        const_iterator begin() const
+        {
+            return const_iterator(nodes_.begin());
+        }
+
+        const_iterator end() const
+        {
+            return const_iterator(nodes_.end());
+        }
+
+        const json_location_node_type& last() const
+        {
+            return *nodes_.back();
+        }
+
+        string_type to_string() const
+        {
+            string_type buffer;
+
+            for (const auto& node : nodes_)
+            {
+                switch (node->node_kind())
+                {
+                    case json_location_node_kind::root:
+                        buffer.append(node->name());
+                        break;
+                    case json_location_node_kind::name:
+                        buffer.push_back('[');
+                        buffer.push_back('\'');
+                        for (auto c : node->name())
+                        {
+                            if (c == '\'')
+                            {
+                                buffer.push_back('\\');
+                                buffer.push_back('\'');
+                            }
+                            else
+                            {
+                                buffer.push_back(c);
+                            }
+                        }
+                        buffer.push_back('\'');
+                        buffer.push_back(']');
+                        break;
+                    case json_location_node_kind::index:
+                        buffer.push_back('[');
+                        jsoncons::detail::from_integer(node->index(), buffer);
+                        buffer.push_back(']');
+                        break;
+                }
+            }
+
+            return buffer;
+        }
+
+        int compare(const json_location& other) const
+        {
+            if (this == &other)
+            {
+               return 0;
+            }
+
+            auto it1 = nodes_.begin();
+            auto it2 = other.nodes_.begin();
+            while (it1 != nodes_.end() && it2 != other.nodes_.end())
+            {
+                int diff = (*it1)->compare_node(*(*it2));
+                if (diff != 0)
+                {
+                    return diff;
+                }
+                ++it1;
+                ++it2;
+            }
+            return (nodes_.size() < other.nodes_.size()) ? -1 : (nodes_.size() == other.nodes_.size()) ? 0 : 1;
+        }
+
+        std::size_t hash() const
+        {
+
+            auto it = nodes_.begin();
+            std::size_t hash = (*it).hash();
+            ++it;
+
+            while (it != nodes_.end())
+            {
+                hash += 17*(*it)->node_hash();
+                ++it;
+            }
+
+            return hash;
+        }
+
+        friend bool operator==(const json_location& lhs, const json_location& rhs) 
+        {
+            return lhs.compare(rhs) == 0;
+        }
+
+        friend bool operator!=(const json_location& lhs, const json_location& rhs)
+        {
+            return !(lhs == rhs);
+        }
+
+        friend bool operator<(const json_location& lhs, const json_location& rhs) 
+        {
+            return lhs.compare(rhs) < 0;
+        }
+    };
+
+    template <class Json>
+    Json* select(Json& root, const json_location<typename Json::char_type>& path)
+    {
+        Json* current = std::addressof(root);
+        for (const auto& json_location_node : path)
+        {
+            if (json_location_node.node_kind() == json_location_node_kind::index)
+            {
+                if (current->type() != json_type::array_value || json_location_node.index() >= current->size())
+                {
+                    return nullptr; 
+                }
+                current = std::addressof(current->at(json_location_node.index()));
+            }
+            else if (json_location_node.node_kind() == json_location_node_kind::name)
+            {
+                if (current->type() != json_type::object_value)
+                {
+                    return nullptr;
+                }
+                auto it = current->find(json_location_node.name());
+                if (it == current->object_range().end())
+                {
+                    return nullptr;
+                }
+                current = std::addressof(it->value());
+            }
+        }
+        return current;
+    }
+
+} // namespace jsonpath
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/json_query.hpp b/include/jsoncons_ext/jsonpath/json_query.hpp
new file mode 100644
index 0000000..8facfa9
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/json_query.hpp
@@ -0,0 +1,115 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSON_QUERY_HPP
+#define JSONCONS_JSONPATH_JSON_QUERY_HPP
+
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_expression.hpp>
+
+namespace jsoncons { 
+namespace jsonpath {
+     
+    template<class Json>
+    Json json_query(const Json& instance,
+                    const typename Json::string_view_type& path, 
+                    result_options options = result_options(),
+                    const custom_functions<Json>& functions = custom_functions<Json>())
+    {
+        auto expr = make_expression<Json>(path, functions);
+        return expr.evaluate(instance, options);
+    }
+
+    template<class Json,class Callback>
+    typename std::enable_if<type_traits::is_binary_function_object<Callback,const std::basic_string<typename Json::char_type>&,const Json&>::value,void>::type
+    json_query(const Json& instance, 
+               const typename Json::string_view_type& path, 
+               Callback callback,
+               result_options options = result_options(),
+               const custom_functions<Json>& functions = custom_functions<Json>())
+    {
+        auto expr = make_expression<Json>(path, functions);
+        expr.evaluate(instance, callback, options);
+    }
+
+    template<class Json, class T>
+    typename std::enable_if<is_json_type_traits_specialized<Json,T>::value,void>::type
+        json_replace(Json& instance, const typename Json::string_view_type& path, T&& new_value,
+                     result_options options = result_options::nodups,
+                     const custom_functions<Json>& funcs = custom_functions<Json>())
+    {
+        using evaluator_t = typename jsoncons::jsonpath::detail::jsonpath_evaluator<Json, Json&>;
+        //using string_type = typename evaluator_t::string_type;
+        using value_type = typename evaluator_t::value_type;
+        using reference = typename evaluator_t::reference;
+        using json_selector_t = typename evaluator_t::path_expression_type;
+        using json_location_type = typename evaluator_t::json_location_type;
+
+        jsoncons::jsonpath::detail::static_resources<value_type,reference> static_resources(funcs);
+        evaluator_t e;
+        json_selector_t expr = e.compile(static_resources, path);
+
+        jsoncons::jsonpath::detail::dynamic_resources<Json,reference> resources;
+        auto callback = [&new_value](const json_location_type&, reference v)
+        {
+            v = std::forward<T>(new_value);
+        };
+        expr.evaluate(resources, instance, resources.root_path_node(), instance, callback, options);
+    }
+
+    template<class Json, class UnaryCallback>
+    typename std::enable_if<type_traits::is_unary_function_object<UnaryCallback,Json>::value,void>::type
+    json_replace(Json& instance, const typename Json::string_view_type& path , UnaryCallback callback)
+    {
+        using evaluator_t = typename jsoncons::jsonpath::detail::jsonpath_evaluator<Json, Json&>;
+        //using string_type = typename evaluator_t::string_type;
+        using value_type = typename evaluator_t::value_type;
+        using reference = typename evaluator_t::reference;
+        using json_selector_t = typename evaluator_t::path_expression_type;
+        using json_location_type = typename evaluator_t::json_location_type;
+
+        jsoncons::jsonpath::detail::static_resources<value_type,reference> static_resources;
+        evaluator_t e;
+        json_selector_t expr = e.compile(static_resources, path);
+
+        jsoncons::jsonpath::detail::dynamic_resources<Json,reference> resources;
+        auto f = [callback](const json_location_type&, reference v)
+        {
+            v = callback(v);
+        };
+        expr.evaluate(resources, instance, resources.root_path_node(), instance, f, result_options::nodups);
+    }
+
+    template<class Json, class BinaryCallback>
+    typename std::enable_if<type_traits::is_binary_function_object<BinaryCallback,const std::basic_string<typename Json::char_type>&,Json&>::value,void>::type
+    json_replace(Json& instance, const typename Json::string_view_type& path , BinaryCallback callback, 
+                 result_options options = result_options::nodups,
+                 const custom_functions<Json>& funcs = custom_functions<Json>())
+    {
+        using evaluator_t = typename jsoncons::jsonpath::detail::jsonpath_evaluator<Json, Json&>;
+        //using string_type = typename evaluator_t::string_type;
+        using value_type = typename evaluator_t::value_type;
+        using reference = typename evaluator_t::reference;
+        using json_selector_t = typename evaluator_t::path_expression_type;
+        using json_location_type = typename evaluator_t::json_location_type;
+
+        jsoncons::jsonpath::detail::static_resources<value_type,reference> static_resources(funcs);
+        evaluator_t e;
+        json_selector_t expr = e.compile(static_resources, path);
+
+        jsoncons::jsonpath::detail::dynamic_resources<Json,reference> resources;
+
+        auto f = [&callback](const json_location_type& path, reference val)
+        {
+            callback(path.to_string(), val);
+        };
+        expr.evaluate(resources, instance, resources.root_path_node(), instance, f, options);
+    }
+
+} // namespace jsonpath
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/jsonpath.hpp b/include/jsoncons_ext/jsonpath/jsonpath.hpp
new file mode 100644
index 0000000..18500c5
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/jsonpath.hpp
@@ -0,0 +1,13 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSONPATH_HPP
+#define JSONCONS_JSONPATH_JSONPATH_HPP
+
+#include <jsoncons_ext/jsonpath/json_query.hpp>
+#include <jsoncons_ext/jsonpath/flatten.hpp>
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/jsonpath_error.hpp b/include/jsoncons_ext/jsonpath/jsonpath_error.hpp
new file mode 100644
index 0000000..8157bba
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/jsonpath_error.hpp
@@ -0,0 +1,240 @@
+/// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSONPATH_ERROR_HPP
+#define JSONCONS_JSONPATH_JSONPATH_ERROR_HPP
+
+#include <jsoncons/json_exception.hpp>
+#include <system_error>
+
+namespace jsoncons { namespace jsonpath {
+
+    enum class jsonpath_errc 
+    {
+        success = 0,
+        expected_root_or_function,
+        expected_current_node,
+        expected_rparen,
+        expected_rbracket,
+        expected_separator,
+        expected_forward_slash,
+        expected_slice_start,
+        expected_slice_end,
+        expected_slice_step,
+        expected_bracket_specifier_or_union,
+        unexpected_operator,
+        invalid_function_name,
+        invalid_argument,
+        invalid_arity,
+        function_name_not_found,
+        parse_error_in_filter,
+        argument_parse_error,
+        unidentified_error,
+        unexpected_eof,
+        expected_colon_dot_left_bracket_comma_or_rbracket,
+        argument_to_unflatten_invalid,
+        invalid_flattened_key,
+        step_cannot_be_zero,
+        invalid_number,
+        illegal_escaped_character,
+        invalid_codepoint,
+        unknown_function,
+        invalid_type,
+        unbalanced_parentheses,
+        syntax_error,
+        expected_comparator,
+        expected_or,
+        expected_and,
+        expected_comma_or_rparen,
+        expected_comma_or_rbracket,
+        expected_relative_path
+    };
+
+    class jsonpath_error_category_impl
+       : public std::error_category
+    {
+    public:
+        const char* name() const noexcept override
+        {
+            return "jsoncons/jsonpath";
+        }
+        std::string message(int ev) const override
+        {
+            switch (static_cast<jsonpath_errc>(ev))
+            {
+                case jsonpath_errc::expected_root_or_function:
+                    return "Expected '$' or function expression";
+                case jsonpath_errc::expected_current_node:
+                    return "Expected @";
+                case jsonpath_errc::expected_rbracket:
+                    return "Expected ]";
+                case jsonpath_errc::expected_rparen:
+                    return "Expected )";
+                case jsonpath_errc::expected_slice_start:
+                    return "Expected slice start";
+                case jsonpath_errc::expected_slice_end:
+                    return "Expected slice end";
+                case jsonpath_errc::expected_slice_step:
+                    return "Expected slice step";
+                case jsonpath_errc::expected_separator:
+                    return "Expected dot or left bracket separator";
+                case jsonpath_errc::expected_forward_slash:
+                    return "Invalid path filter, expected '/'";
+                case jsonpath_errc::expected_bracket_specifier_or_union:
+                    return "Expected index, single or double quoted name, expression, filter, absolute ('$') path or relative ('@') path";
+                case jsonpath_errc::invalid_function_name:
+                    return "Invalid function name";
+                case jsonpath_errc::invalid_argument:
+                    return "Invalid argument type";
+                case jsonpath_errc::invalid_arity:
+                    return "Incorrect number of arguments";
+                case jsonpath_errc::function_name_not_found:
+                    return "Function name not found";
+                case jsonpath_errc::parse_error_in_filter:
+                    return "Could not parse JSON expression in a JSONPath filter";
+                case jsonpath_errc::argument_parse_error:
+                    return "Could not parse JSON expression passed to JSONPath function";
+                case jsonpath_errc::unidentified_error:
+                    return "Unidentified error";
+                case jsonpath_errc::unexpected_eof:
+                    return "Unexpected EOF while parsing jsonpath expression";
+                case jsonpath_errc::expected_colon_dot_left_bracket_comma_or_rbracket:
+                    return "Expected ':', '.', '[', ',', or ']'";
+                case jsonpath_errc::argument_to_unflatten_invalid:
+                    return "Argument to unflatten must be an object";
+                case jsonpath_errc::invalid_flattened_key:
+                    return "Flattened key is invalid";
+                case jsonpath_errc::step_cannot_be_zero:
+                    return "Slice step cannot be zero";
+                case jsonpath_errc::invalid_number:
+                    return "Invalid number";
+                case jsonpath_errc::illegal_escaped_character:
+                    return "Illegal escaped character";
+                case jsonpath_errc::invalid_codepoint:
+                    return "Invalid codepoint";
+                case jsonpath_errc::unknown_function:
+                    return "Unknown function";
+                case jsonpath_errc::invalid_type:
+                    return "Invalid type";
+                case jsonpath_errc::unbalanced_parentheses:
+                    return "Unbalanced parentheses";
+                case jsonpath_errc::syntax_error:
+                    return "Syntax error";
+                case jsonpath_errc::expected_comparator:
+                    return "Expected comparator";
+                case jsonpath_errc::expected_or:
+                    return "Expected operator '||'";
+                case jsonpath_errc::expected_and:
+                    return "Expected operator '&&'";
+                case jsonpath_errc::expected_comma_or_rparen:
+                    return "Expected comma or right parenthesis";
+                case jsonpath_errc::expected_comma_or_rbracket:
+                    return "Expected comma or right bracket";
+                case jsonpath_errc::expected_relative_path:
+                    return "Expected unquoted string, or single or double quoted string, or index or '*'";
+                default:
+                    return "Unknown jsonpath parser error";
+            }
+        }
+    };
+
+    inline
+    const std::error_category& jsonpath_error_category()
+    {
+      static jsonpath_error_category_impl instance;
+      return instance;
+    }
+
+    inline 
+    std::error_code make_error_code(jsonpath_errc result)
+    {
+        return std::error_code(static_cast<int>(result),jsonpath_error_category());
+    }
+
+} // jsonpath
+} // jsoncons
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::jsonpath::jsonpath_errc> : public true_type
+    {
+    };
+}
+
+namespace jsoncons { namespace jsonpath {
+
+    class jsonpath_error : public std::system_error, public virtual json_exception
+    {
+        std::size_t line_number_;
+        std::size_t column_number_;
+        mutable std::string what_;
+    public:
+        jsonpath_error(std::error_code ec)
+            : std::system_error(ec), line_number_(0), column_number_(0)
+        {
+        }
+        jsonpath_error(std::error_code ec, const std::string& what_arg)
+            : std::system_error(ec, what_arg), line_number_(0), column_number_(0)
+        {
+        }
+        jsonpath_error(std::error_code ec, std::size_t position)
+            : std::system_error(ec), line_number_(0), column_number_(position)
+        {
+        }
+        jsonpath_error(std::error_code ec, std::size_t line, std::size_t column)
+            : std::system_error(ec), line_number_(line), column_number_(column)
+        {
+        }
+        jsonpath_error(const jsonpath_error& other) = default;
+
+        jsonpath_error(jsonpath_error&& other) = default;
+
+        const char* what() const noexcept override
+        {
+            if (what_.empty())
+            {
+                JSONCONS_TRY
+                {
+                    what_.append(std::system_error::what());
+                    if (line_number_ != 0 && column_number_ != 0)
+                    {
+                        what_.append(" at line ");
+                        what_.append(std::to_string(line_number_));
+                        what_.append(" and column ");
+                        what_.append(std::to_string(column_number_));
+                    }
+                    else if (column_number_ != 0)
+                    {
+                        what_.append(" at position ");
+                        what_.append(std::to_string(column_number_));
+                    }
+                    return what_.c_str();
+                }
+                JSONCONS_CATCH(...)
+                {
+                    return std::system_error::what();
+                }
+            }
+            else
+            {
+                return what_.c_str();
+            }
+        }
+
+        std::size_t line() const noexcept
+        {
+            return line_number_;
+        }
+
+        std::size_t column() const noexcept
+        {
+            return column_number_;
+        }
+    };
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp b/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp
new file mode 100644
index 0000000..a3537b3
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp
@@ -0,0 +1,2612 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSONPATH_EXPRESSION_HPP
+#define JSONCONS_JSONPATH_JSONPATH_EXPRESSION_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::is_const
+#include <limits> // std::numeric_limits
+#include <utility> // std::move
+#include <regex>
+#include <algorithm> // std::reverse
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_error.hpp>
+#include <jsoncons_ext/jsonpath/expression.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_selector.hpp>
+
+namespace jsoncons { 
+namespace jsonpath {
+namespace detail {
+     
+    enum class path_state 
+    {
+        start,
+        root_or_current_node,
+        expect_function_expr,
+        relative_path,
+        relative_location,
+        parent_operator,
+        ancestor_depth,
+        filter_expression,
+        expression_rhs,
+        recursive_descent_or_expression_lhs,
+        path_or_literal_or_function,
+        json_text_or_function,
+        json_text_or_function_name,
+        json_text_string,
+        json_value,
+        json_string,
+        identifier_or_function_expr,
+        name_or_lbracket,
+        unquoted_string,
+        anything,
+        number,
+        function_expression,
+        argument,
+        zero_or_one_arguments,
+        one_or_more_arguments,
+        identifier,
+        single_quoted_string,
+        double_quoted_string,
+        bracketed_unquoted_name_or_union,
+        union_expression,
+        identifier_or_union,
+        bracket_specifier_or_union,
+        bracketed_wildcard,
+        index_or_slice,
+        wildcard_or_union,
+        union_element,
+        index_or_slice_or_union,
+        integer,
+        digit,
+        slice_expression_stop,
+        slice_expression_step,
+        comma_or_rbracket,
+        expect_rparen,
+        expect_rbracket,
+        quoted_string_escape_char,
+        escape_u1, 
+        escape_u2, 
+        escape_u3, 
+        escape_u4, 
+        escape_expect_surrogate_pair1, 
+        escape_expect_surrogate_pair2, 
+        escape_u5, 
+        escape_u6, 
+        escape_u7, 
+        escape_u8,
+        expression,
+        comparator_expression,
+        eq_or_regex,
+        expect_regex,
+        regex,
+        regex_options,
+        regex_pattern,
+        cmp_lt_or_lte,
+        cmp_gt_or_gte,
+        cmp_ne,
+        expect_or,
+        expect_and
+    };
+
+    template<class Json,
+             class JsonReference>
+    class jsonpath_evaluator : public ser_context
+    {
+    public:
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type,std::char_traits<char_type>>;
+        using string_view_type = typename Json::string_view_type;
+        using path_value_pair_type = path_value_pair<Json,JsonReference>;
+        using value_type = Json;
+        using reference = JsonReference;
+        using pointer = typename path_value_pair_type::value_pointer;
+        using token_type = token<Json,JsonReference>;
+        using path_expression_type = path_expression<Json,JsonReference>;
+        using expression_type = expression<Json,JsonReference>;
+        using json_location_type = json_location<char_type>;
+        using json_location_node_type = json_location_node<char_type>;
+        using selector_type = jsonpath_selector<Json,JsonReference>;
+
+    private:
+
+        std::size_t line_;
+        std::size_t column_;
+        const char_type* begin_input_;
+        const char_type* end_input_;
+        const char_type* p_;
+
+        using argument_type = std::vector<pointer>;
+        std::vector<argument_type> function_stack_;
+        std::vector<path_state> state_stack_;
+        std::vector<token_type> output_stack_;
+        std::vector<token_type> operator_stack_;
+
+    public:
+        jsonpath_evaluator()
+            : line_(1), column_(1),
+              begin_input_(nullptr), end_input_(nullptr),
+              p_(nullptr)
+        {
+        }
+
+        jsonpath_evaluator(std::size_t line, std::size_t column)
+            : line_(line), column_(column),
+              begin_input_(nullptr), end_input_(nullptr),
+              p_(nullptr)
+        {
+        }
+
+        std::size_t line() const
+        {
+            return line_;
+        }
+
+        std::size_t column() const
+        {
+            return column_;
+        }
+
+        path_expression_type compile(static_resources<value_type,reference>& resources, const string_view_type& path)
+        {
+            std::error_code ec;
+            auto result = compile(resources, path, ec);
+            if (ec)
+            {
+                JSONCONS_THROW(jsonpath_error(ec, line_, column_));
+            }
+            return result;
+        }
+
+        path_expression_type compile(static_resources<value_type,reference>& resources, 
+                                     const string_view_type& path, 
+                                     std::error_code& ec)
+        {
+            std::size_t selector_id = 0;
+
+            string_type buffer;
+            string_type buffer2;
+            uint32_t cp = 0;
+            uint32_t cp2 = 0;
+
+            begin_input_ = path.data();
+            end_input_ = path.data() + path.length();
+            p_ = begin_input_;
+
+            slice slic;
+            bool paths_required = false;
+            int ancestor_depth = 0;
+
+            state_stack_.emplace_back(path_state::start);
+            while (p_ < end_input_ && !state_stack_.empty())
+            {
+                switch (state_stack_.back())
+                {
+                    case path_state::start: 
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '$':
+                            case '@':
+                            {
+                                push_token(resources, token_type(resources.new_selector(current_node_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.emplace_back(path_state::relative_location);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                            {
+                                state_stack_.emplace_back(path_state::relative_location);
+                                state_stack_.emplace_back(path_state::expect_function_expr);
+                                state_stack_.emplace_back(path_state::unquoted_string);
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case path_state::root_or_current_node: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '$':
+                                push_token(resources, token_type(root_node_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(root_selector<Json,JsonReference>(selector_id++))), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '@':
+                                push_token(resources, token_type(current_node_arg), ec); // ISSUE
+                                push_token(resources, token_type(resources.new_selector(current_node_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::syntax_error;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::recursive_descent_or_expression_lhs:
+                        switch (*p_)
+                        {
+                            case '.':
+                                push_token(resources, token_type(resources.new_selector(recursive_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::name_or_lbracket;
+                                break;
+                            default:
+                                state_stack_.back() = path_state::relative_path;
+                                break;
+                        }
+                        break;
+                    case path_state::name_or_lbracket: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '[': // [ can follow ..
+                                state_stack_.back() = path_state::bracket_specifier_or_union;
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.clear();
+                                state_stack_.back() = path_state::relative_path;
+                                break;
+                        }
+                        break;
+                    case path_state::json_string:
+                    {
+                        //std::cout << "literal: " << buffer << "\n";
+                        push_token(resources, token_type(literal_arg, Json(buffer)), ec);
+                        if (ec) {return path_expression_type();}
+                        buffer.clear();
+                        state_stack_.pop_back(); // json_value
+                        break;
+                    }
+                    case path_state::path_or_literal_or_function: 
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '$':
+                            case '@':
+                                state_stack_.back() = path_state::relative_location;
+                                state_stack_.push_back(path_state::root_or_current_node);
+                                break;
+                            case '(':
+                            {
+                                ++p_;
+                                ++column_;
+                                push_token(resources, lparen_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::expect_rparen;
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                break;
+                            }
+                            case '\'':
+                                state_stack_.back() = path_state::json_string;
+                                state_stack_.emplace_back(path_state::single_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::json_string;
+                                state_stack_.emplace_back(path_state::double_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '!':
+                            {
+                                ++p_;
+                                ++column_;
+                                push_token(resources, token_type(resources.get_unary_not()), ec);
+                                if (ec) {return path_expression_type();}
+                                break;
+                            }
+                            case '-':
+                            {
+                                ++p_;
+                                ++column_;
+                                push_token(resources, token_type(resources.get_unary_minus()), ec);
+                                if (ec) {return path_expression_type();}
+                                break;
+                            }
+                            case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                            {
+                                state_stack_.back() = path_state::json_value;
+                                state_stack_.emplace_back(path_state::number);
+                                break;
+                            }
+                            default:
+                            {
+                                state_stack_.back() = path_state::json_text_or_function_name;
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case path_state::json_text_or_function:
+                    {
+                        switch(*p_)
+                        {
+                            case '(':
+                            {
+                                auto f = resources.get_function(buffer, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                buffer.clear();
+                                push_token(resources, current_node_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                push_token(resources, token_type(f), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::function_expression;
+                                state_stack_.emplace_back(path_state::zero_or_one_arguments);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                            {
+                                json_decoder<Json> decoder;
+                                basic_json_parser<char_type> parser;
+                                parser.update(buffer.data(),buffer.size());
+                                parser.parse_some(decoder, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                parser.finish_parse(decoder, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                push_token(resources, token_type(literal_arg, decoder.get_result()), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back();
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case path_state::json_value:
+                    {
+                        json_decoder<Json> decoder;
+                        basic_json_parser<char_type> parser;
+                        parser.update(buffer.data(),buffer.size());
+                        parser.parse_some(decoder, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        parser.finish_parse(decoder, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        push_token(resources, token_type(literal_arg, decoder.get_result()), ec);
+                        if (ec) {return path_expression_type();}
+                        buffer.clear();
+                        state_stack_.pop_back();
+                        break;
+                    }
+                    case path_state::json_text_or_function_name:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '{':
+                            case '[':
+                            {
+                                json_decoder<Json> decoder;
+                                basic_json_parser<char_type> parser;
+                                parser.update(p_,end_input_ - p_);
+                                parser.parse_some(decoder, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                parser.finish_parse(decoder, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                push_token(resources, token_type(literal_arg, decoder.get_result()), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back();
+                                p_ = parser.current();
+                                column_ = column_ + parser.column() - 1;
+                                break;
+                            }
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                state_stack_.back() = path_state::json_text_or_function;
+                                state_stack_.emplace_back(path_state::number);
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::json_text_or_function;
+                                state_stack_.emplace_back(path_state::json_text_string);
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.back() = path_state::json_text_or_function;
+                                state_stack_.emplace_back(path_state::unquoted_string);
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+                    case path_state::number: 
+                        switch (*p_)
+                        {
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                            case 'e':case 'E':case '.':
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.pop_back(); // number
+                                break;
+                        };
+                        break;
+                    case path_state::json_text_string: 
+                        switch (*p_)
+                        {
+                            case '\\':
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                if (p_ == end_input_)
+                                {
+                                    ec = jsonpath_errc::unexpected_eof;
+                                    return path_expression_type();
+                                }
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\"':
+                                buffer.push_back(*p_);
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+                    case path_state::relative_path: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '*':
+                                push_token(resources, token_type(resources.new_selector(wildcard_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\'':
+                                state_stack_.back() = path_state::identifier;
+                                state_stack_.emplace_back(path_state::single_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::identifier;
+                                state_stack_.emplace_back(path_state::double_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                            case '.':
+                                ec = jsonpath_errc::expected_relative_path;
+                                return path_expression_type();
+                            default:
+                                buffer.clear();
+                                state_stack_.back() = path_state::identifier_or_function_expr;
+                                state_stack_.emplace_back(path_state::unquoted_string);
+                                break;
+                        }
+                        break;
+                    case path_state::identifier_or_function_expr:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '(':
+                            {
+                                auto f = resources.get_function(buffer, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                buffer.clear();
+                                push_token(resources, current_node_arg, ec);
+                                push_token(resources, token_type(f), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::function_expression;
+                                state_stack_.emplace_back(path_state::zero_or_one_arguments);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                            {
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back(); 
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case path_state::expect_function_expr:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '(':
+                            {
+                                auto f = resources.get_function(buffer, ec);
+                                if (ec)
+                                {
+                                    return path_expression_type();
+                                }
+                                buffer.clear();
+                                push_token(resources, current_node_arg, ec);
+                                push_token(resources, token_type(f), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::function_expression;
+                                state_stack_.emplace_back(path_state::zero_or_one_arguments);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                            {
+                                ec = jsonpath_errc::expected_root_or_function;
+                                return path_expression_type();
+                            }
+                        }
+                        break;
+                    }
+                    case path_state::function_expression:
+                    {
+                        
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ',':
+                                push_token(resources, token_type(current_node_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                push_token(resources, token_type(begin_expression_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                if (ec) {return path_expression_type();}
+                                state_stack_.emplace_back(path_state::argument);
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ')':
+                            {
+                                push_token(resources, token_type(end_function_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jsonpath_errc::syntax_error;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::zero_or_one_arguments:
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ')':
+                                state_stack_.pop_back();
+                                break;
+                            default:
+                                push_token(resources, token_type(begin_expression_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::one_or_more_arguments;
+                                state_stack_.emplace_back(path_state::argument);
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::one_or_more_arguments:
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ')':
+                                state_stack_.pop_back();
+                                break;
+                            case ',':
+                                push_token(resources, token_type(begin_expression_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.emplace_back(path_state::argument);
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                ++p_;
+                                ++column_;
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::argument:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ',':
+                            case ')':
+                            {
+                                push_token(resources, token_type(end_argument_expression_arg), ec);
+                                push_token(resources, argument_arg, ec);
+                                //push_token(resources, argument_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                break;
+                            }
+                            default:
+                                ec = jsonpath_errc::expected_comma_or_rparen;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::unquoted_string: 
+                        switch (*p_)
+                        {
+                            case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':case 'g':case 'h':case 'i':case 'j':case 'k':case 'l':case 'm':case 'n':case 'o':case 'p':case 'q':case 'r':case 's':case 't':case 'u':case 'v':case 'w':case 'x':case 'y':case 'z':
+                            case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':case 'G':case 'H':case 'I':case 'J':case 'K':case 'L':case 'M':case 'N':case 'O':case 'P':case 'Q':case 'R':case 'S':case 'T':case 'U':case 'V':case 'W':case 'X':case 'Y':case 'Z':
+                            case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                            case '_':
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                if (typename std::make_unsigned<char_type>::type(*p_) > 127)
+                                {
+                                    buffer.push_back(*p_);
+                                    ++p_;
+                                    ++column_;
+                                }
+                                else
+                                {
+                                    state_stack_.pop_back(); // unquoted_string
+                                }
+                                break;
+                        };
+                        break;                    
+                    case path_state::relative_location: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '.':
+                                state_stack_.emplace_back(path_state::recursive_descent_or_expression_lhs);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                                state_stack_.emplace_back(path_state::bracket_specifier_or_union);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '^':
+                                ancestor_depth = 0;
+                                state_stack_.emplace_back(path_state::parent_operator);
+                                state_stack_.emplace_back(path_state::ancestor_depth);
+                                break;
+                            default:
+                                state_stack_.pop_back();
+                                break;
+                        };
+                        break;
+                    case path_state::parent_operator: 
+                    {
+                        push_token(resources, token_type(resources.new_selector(parent_node_selector<Json,JsonReference>(ancestor_depth))), ec);
+                        paths_required = true;
+                        ancestor_depth = 0;
+                        ++p_;
+                        ++column_;
+                        state_stack_.pop_back();
+                        break;
+                    }
+                    case path_state::ancestor_depth: 
+                    {
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '^':
+                            {
+                                ++ancestor_depth;
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                            {
+                                state_stack_.pop_back();
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case path_state::expression_rhs: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '.':
+                                state_stack_.emplace_back(path_state::recursive_descent_or_expression_lhs);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                                state_stack_.emplace_back(path_state::bracket_specifier_or_union);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ')':
+                            {
+                                state_stack_.pop_back();
+                                break;
+                            }
+                            case '|':
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                state_stack_.emplace_back(path_state::expect_or);
+                                break;
+                            case '&':
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                state_stack_.emplace_back(path_state::expect_and);
+                                break;
+                            case '<':
+                            case '>':
+                            {
+                                state_stack_.emplace_back(path_state::comparator_expression);
+                                break;
+                            }
+                            case '=':
+                            {
+                                state_stack_.emplace_back(path_state::eq_or_regex);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '!':
+                            {
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                state_stack_.emplace_back(path_state::cmp_ne);
+                                break;
+                            }
+                            case '+':
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                push_token(resources, token_type(resources.get_plus_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '-':
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                push_token(resources, token_type(resources.get_minus_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '*':
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                push_token(resources, token_type(resources.get_mult_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '/':
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                push_token(resources, token_type(resources.get_div_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '%':
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                push_token(resources, token_type(resources.get_modulus_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ']':
+                            case ',':
+                                state_stack_.pop_back();
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_separator;
+                                return path_expression_type();
+                        };
+                        break;
+                    case path_state::expect_or:
+                    {
+                        switch (*p_)
+                        {
+                            case '|':
+                                push_token(resources, token_type(resources.get_or_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_or;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::expect_and:
+                    {
+                        switch(*p_)
+                        {
+                            case '&':
+                                push_token(resources, token_type(resources.get_and_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back(); // expect_and
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_and;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::comparator_expression:
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '<':
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::path_or_literal_or_function;
+                                state_stack_.emplace_back(path_state::cmp_lt_or_lte);
+                                break;
+                            case '>':
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::path_or_literal_or_function;
+                                state_stack_.emplace_back(path_state::cmp_gt_or_gte);
+                                break;
+                            default:
+                                if (state_stack_.size() > 1)
+                                {
+                                    state_stack_.pop_back();
+                                }
+                                else
+                                {
+                                    ec = jsonpath_errc::syntax_error;
+                                    return path_expression_type();
+                                }
+                                break;
+                        }
+                        break;
+                    case path_state::eq_or_regex:
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '=':
+                            {
+                                push_token(resources, token_type(resources.get_eq_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::path_or_literal_or_function;
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '~':
+                            {
+                                ++p_;
+                                ++column_;
+                                state_stack_.emplace_back(path_state::expect_regex);
+                                break;
+                            }
+                            default:
+                                if (state_stack_.size() > 1)
+                                {
+                                    state_stack_.pop_back();
+                                }
+                                else
+                                {
+                                    ec = jsonpath_errc::syntax_error;
+                                    return path_expression_type();
+                                }
+                                break;
+                        }
+                        break;
+                    case path_state::expect_regex: 
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '/':
+                                state_stack_.back() = path_state::regex;
+                                state_stack_.emplace_back(path_state::regex_options);
+                                state_stack_.emplace_back(path_state::regex_pattern);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default: 
+                                ec = jsonpath_errc::expected_forward_slash;
+                                return path_expression_type();
+                        };
+                        break;
+                    case path_state::regex: 
+                    {
+                        std::regex::flag_type options = std::regex_constants::ECMAScript; 
+                        if (buffer2.find('i') != string_type::npos)
+                        {
+                            options |= std::regex_constants::icase;
+                        }
+                        std::basic_regex<char_type> pattern(buffer, options);
+                        push_token(resources, resources.get_regex_operator(std::move(pattern)), ec);
+                        if (ec) {return path_expression_type();}
+                        buffer.clear();
+                        buffer2.clear();
+                        state_stack_.pop_back();
+                        break;
+                    }
+                    case path_state::regex_pattern: 
+                    {
+                        switch (*p_)
+                        {                   
+                            case '/':
+                                {
+                                    state_stack_.pop_back();
+                                    ++p_;
+                                    ++column_;
+                                }
+                                break;
+
+                            default: 
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::regex_options: 
+                    {
+                        if (*p_ == 'i')
+                        {           
+                            buffer2.push_back(*p_);
+                            ++p_;
+                            ++column_;
+                        }
+                        else
+                        {
+                            state_stack_.pop_back();
+                        }
+                        break;
+                    }
+                    case path_state::cmp_lt_or_lte:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(resources, token_type(resources.get_lte_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                push_token(resources, token_type(resources.get_lt_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::cmp_gt_or_gte:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(resources, token_type(resources.get_gte_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                //std::cout << "Parse: gt_operator\n";
+                                push_token(resources, token_type(resources.get_gt_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back(); 
+                                break;
+                        }
+                        break;
+                    }
+                    case path_state::cmp_ne:
+                    {
+                        switch(*p_)
+                        {
+                            case '=':
+                                push_token(resources, token_type(resources.get_ne_operator()), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back(); 
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_comparator;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::identifier:
+                        push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                        if (ec) {return path_expression_type();}
+                        buffer.clear();
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::single_quoted_string:
+                        switch (*p_)
+                        {
+                            case '\'':
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\\':
+                                state_stack_.emplace_back(path_state::quoted_string_escape_char);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+                    case path_state::double_quoted_string: 
+                        switch (*p_)
+                        {
+                            case '\"':
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\\':
+                                state_stack_.emplace_back(path_state::quoted_string_escape_char);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        };
+                        break;
+                    case path_state::comma_or_rbracket:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ',':
+                                state_stack_.back() = path_state::bracket_specifier_or_union;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ']':
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_comma_or_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::expect_rbracket:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']':
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::expect_rparen:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ')':
+                                ++p_;
+                                ++column_;
+                                push_token(resources, rparen_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::expression_rhs;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rparen;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::bracket_specifier_or_union:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '(':
+                            {
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(begin_expression_arg), ec);
+                                push_token(resources, lparen_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::expression);
+                                state_stack_.emplace_back(path_state::expect_rparen);
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '?':
+                            {
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(begin_filter_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::filter_expression);
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '*':
+                                state_stack_.back() = path_state::wildcard_or_union;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\'':
+                                state_stack_.back() = path_state::identifier_or_union;
+                                state_stack_.push_back(path_state::single_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::identifier_or_union;
+                                state_stack_.push_back(path_state::double_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ':': // slice_expression
+                                state_stack_.back() = path_state::index_or_slice_or_union;
+                                break;
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                state_stack_.back() = path_state::index_or_slice_or_union;
+                                state_stack_.emplace_back(path_state::integer);
+                                break;
+                            case '$':
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, root_node_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::relative_location);                                
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '@':
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(current_node_arg), ec); // ISSUE
+                                push_token(resources, token_type(resources.new_selector(current_node_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::relative_location);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_bracket_specifier_or_union;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::union_element:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ':': // slice_expression
+                                state_stack_.back() = path_state::index_or_slice;
+                                break;
+                            case '-':case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                state_stack_.back() = path_state::index_or_slice;
+                                state_stack_.emplace_back(path_state::integer);
+                                break;
+                            case '(':
+                            {
+                                push_token(resources, token_type(begin_expression_arg), ec);
+                                push_token(resources, lparen_arg, ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::expression;
+                                state_stack_.emplace_back(path_state::expect_rparen);
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '?':
+                            {
+                                push_token(resources, token_type(begin_filter_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::filter_expression;
+                                state_stack_.emplace_back(path_state::expression_rhs);
+                                state_stack_.emplace_back(path_state::path_or_literal_or_function);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case '*':
+                                push_token(resources, token_type(resources.new_selector(wildcard_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::relative_location;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '$':
+                                push_token(resources, token_type(root_node_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(root_selector<Json,JsonReference>(selector_id++))), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::relative_location;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '@':
+                                push_token(resources, token_type(current_node_arg), ec); // ISSUE
+                                push_token(resources, token_type(resources.new_selector(current_node_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::relative_location;
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\'':
+                                state_stack_.back() = path_state::identifier;
+                                state_stack_.push_back(path_state::single_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '\"':
+                                state_stack_.back() = path_state::identifier;
+                                state_stack_.push_back(path_state::double_quoted_string);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_bracket_specifier_or_union;
+                                return path_expression_type();
+                        }
+                        break;
+
+                    case path_state::integer:
+                        switch(*p_)
+                        {
+                            case '-':
+                                buffer.push_back(*p_);
+                                state_stack_.back() = path_state::digit;
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.back() = path_state::digit;
+                                break;
+                        }
+                        break;
+                    case path_state::digit:
+                        switch(*p_)
+                        {
+                            case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                state_stack_.pop_back(); // digit
+                                break;
+                        }
+                        break;
+                    case path_state::index_or_slice_or_union:
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']':
+                            {
+                                if (buffer.empty())
+                                {
+                                    ec = jsonpath_errc::invalid_number;
+                                    return path_expression_type();
+                                }
+                                int64_t n{0};
+                                auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                                if (!r)
+                                {
+                                    ec = jsonpath_errc::invalid_number;
+                                    return path_expression_type();
+                                }
+                                push_token(resources, token_type(resources.new_selector(index_selector<Json,JsonReference>(n))), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back(); // index_or_slice_or_union
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case ',':
+                            {
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                if (buffer.empty())
+                                {
+                                    ec = jsonpath_errc::invalid_number;
+                                    return path_expression_type();
+                                }
+                                else
+                                {
+                                    int64_t n{0};
+                                    auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                                    if (!r)
+                                    {
+                                        ec = jsonpath_errc::invalid_number;
+                                        return path_expression_type();
+                                    }
+                                    push_token(resources, token_type(resources.new_selector(index_selector<Json,JsonReference>(n))), ec);
+                                    if (ec) {return path_expression_type();}
+
+                                    buffer.clear();
+                                }
+                                push_token(resources, token_type(separator_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::union_element);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            case ':':
+                            {
+                                if (!buffer.empty())
+                                {
+                                    int64_t n{0};
+                                    auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                                    if (!r)
+                                    {
+                                        ec = jsonpath_errc::invalid_number;
+                                        return path_expression_type();
+                                    }
+                                    slic.start_ = n;
+                                    buffer.clear();
+                                }
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::slice_expression_stop);
+                                state_stack_.emplace_back(path_state::integer);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::slice_expression_stop:
+                    {
+                        if (!buffer.empty())
+                        {
+                            int64_t n{0};
+                            auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                            if (!r)
+                            {
+                                ec = jsonpath_errc::invalid_number;
+                                return path_expression_type();
+                            }
+                            slic.stop_ = jsoncons::optional<int64_t>(n);
+                            buffer.clear();
+                        }
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']':
+                            case ',':
+                                push_token(resources, token_type(resources.new_selector(slice_selector<Json,JsonReference>(slic))), ec);
+                                if (ec) {return path_expression_type();}
+                                slic = slice{};
+                                state_stack_.pop_back(); // bracket_specifier2
+                                break;
+                            case ':':
+                                state_stack_.back() = path_state::slice_expression_step;
+                                state_stack_.emplace_back(path_state::integer);
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::slice_expression_step:
+                    {
+                        if (!buffer.empty())
+                        {
+                            int64_t n{0};
+                            auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                            if (!r)
+                            {
+                                ec = jsonpath_errc::invalid_number;
+                                return path_expression_type();
+                            }
+                            if (n == 0)
+                            {
+                                ec = jsonpath_errc::step_cannot_be_zero;
+                                return path_expression_type();
+                            }
+                            slic.step_ = n;
+                            buffer.clear();
+                        }
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']':
+                            case ',':
+                                push_token(resources, token_type(resources.new_selector(slice_selector<Json,JsonReference>(slic))), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                slic = slice{};
+                                state_stack_.pop_back(); // slice_expression_step
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+
+                    case path_state::bracketed_unquoted_name_or_union:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']': 
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '.':
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::relative_path);                                
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::relative_path);                                
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ',': 
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                push_token(resources, token_type(separator_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::relative_path);                                
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                buffer.push_back(*p_);
+                                ++p_;
+                                ++column_;
+                                break;
+                        }
+                        break;
+                    case path_state::union_expression:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '.':
+                                state_stack_.emplace_back(path_state::relative_path);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case '[':
+                                state_stack_.emplace_back(path_state::bracket_specifier_or_union);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ',': 
+                                push_token(resources, token_type(separator_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.emplace_back(path_state::union_element);
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ']': 
+                                push_token(resources, token_type(end_union_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::identifier_or_union:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']': 
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ',': 
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                                push_token(resources, token_type(separator_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::union_element);                                
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::bracketed_wildcard:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case '[':
+                            case ']':
+                            case ',':
+                            case '.':
+                                push_token(resources, token_type(resources.new_selector(wildcard_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back();
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::index_or_slice:
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ',':
+                            case ']':
+                            {
+                                if (buffer.empty())
+                                {
+                                    ec = jsonpath_errc::invalid_number;
+                                    return path_expression_type();
+                                }
+                                else
+                                {
+                                    int64_t n{0};
+                                    auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                                    if (!r)
+                                    {
+                                        ec = jsonpath_errc::invalid_number;
+                                        return path_expression_type();
+                                    }
+                                    push_token(resources, token_type(resources.new_selector(index_selector<Json,JsonReference>(n))), ec);
+                                    if (ec) {return path_expression_type();}
+
+                                    buffer.clear();
+                                }
+                                state_stack_.pop_back(); // bracket_specifier
+                                break;
+                            }
+                            case ':':
+                            {
+                                if (!buffer.empty())
+                                {
+                                    int64_t n{0};
+                                    auto r = jsoncons::detail::to_integer(buffer.data(), buffer.size(), n);
+                                    if (!r)
+                                    {
+                                        ec = jsonpath_errc::invalid_number;
+                                        return path_expression_type();
+                                    }
+                                    slic.start_ = n;
+                                    buffer.clear();
+                                }
+                                state_stack_.back() = path_state::slice_expression_stop;
+                                state_stack_.emplace_back(path_state::integer);
+                                ++p_;
+                                ++column_;
+                                break;
+                            }
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::wildcard_or_union:
+                        switch (*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ']': 
+                                push_token(resources, token_type(resources.new_selector(wildcard_selector<Json,JsonReference>())), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.pop_back();
+                                ++p_;
+                                ++column_;
+                                break;
+                            case ',': 
+                                push_token(resources, token_type(begin_union_arg), ec);
+                                push_token(resources, token_type(resources.new_selector(wildcard_selector<Json,JsonReference>())), ec);
+                                push_token(resources, token_type(separator_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                buffer.clear();
+                                state_stack_.back() = path_state::union_expression; // union
+                                state_stack_.emplace_back(path_state::union_element);                                
+                                ++p_;
+                                ++column_;
+                                break;
+                            default:
+                                ec = jsonpath_errc::expected_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::quoted_string_escape_char:
+                        switch (*p_)
+                        {
+                            case '\"':
+                                buffer.push_back('\"');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case '\'':
+                                buffer.push_back('\'');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case '\\': 
+                                buffer.push_back('\\');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case '/':
+                                buffer.push_back('/');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'b':
+                                buffer.push_back('\b');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'f':
+                                buffer.push_back('\f');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'n':
+                                buffer.push_back('\n');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'r':
+                                buffer.push_back('\r');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 't':
+                                buffer.push_back('\t');
+                                ++p_;
+                                ++column_;
+                                state_stack_.pop_back();
+                                break;
+                            case 'u':
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::escape_u1;
+                                break;
+                            default:
+                                ec = jsonpath_errc::illegal_escaped_character;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::escape_u1:
+                        cp = append_to_codepoint(0, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u2;
+                        break;
+                    case path_state::escape_u2:
+                        cp = append_to_codepoint(cp, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u3;
+                        break;
+                    case path_state::escape_u3:
+                        cp = append_to_codepoint(cp, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u4;
+                        break;
+                    case path_state::escape_u4:
+                        cp = append_to_codepoint(cp, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        if (unicode_traits::is_high_surrogate(cp))
+                        {
+                            ++p_;
+                            ++column_;
+                            state_stack_.back() = path_state::escape_expect_surrogate_pair1;
+                        }
+                        else
+                        {
+                            unicode_traits::convert(&cp, 1, buffer);
+                            ++p_;
+                            ++column_;
+                            state_stack_.pop_back();
+                        }
+                        break;
+                    case path_state::escape_expect_surrogate_pair1:
+                        switch (*p_)
+                        {
+                            case '\\': 
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::escape_expect_surrogate_pair2;
+                                break;
+                            default:
+                                ec = jsonpath_errc::invalid_codepoint;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::escape_expect_surrogate_pair2:
+                        switch (*p_)
+                        {
+                            case 'u': 
+                                ++p_;
+                                ++column_;
+                                state_stack_.back() = path_state::escape_u5;
+                                break;
+                            default:
+                                ec = jsonpath_errc::invalid_codepoint;
+                                return path_expression_type();
+                        }
+                        break;
+                    case path_state::escape_u5:
+                        cp2 = append_to_codepoint(0, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u6;
+                        break;
+                    case path_state::escape_u6:
+                        cp2 = append_to_codepoint(cp2, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u7;
+                        break;
+                    case path_state::escape_u7:
+                        cp2 = append_to_codepoint(cp2, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        ++p_;
+                        ++column_;
+                        state_stack_.back() = path_state::escape_u8;
+                        break;
+                    case path_state::escape_u8:
+                    {
+                        cp2 = append_to_codepoint(cp2, *p_, ec);
+                        if (ec)
+                        {
+                            return path_expression_type();
+                        }
+                        uint32_t codepoint = 0x10000 + ((cp & 0x3FF) << 10) + (cp2 & 0x3FF);
+                        unicode_traits::convert(&codepoint, 1, buffer);
+                        state_stack_.pop_back();
+                        ++p_;
+                        ++column_;
+                        break;
+                    }
+                    case path_state::filter_expression:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ',':
+                            case ']':
+                            {
+                                push_token(resources, token_type(end_filter_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                break;
+                            }
+                            default:
+                                ec = jsonpath_errc::expected_comma_or_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    case path_state::expression:
+                    {
+                        switch(*p_)
+                        {
+                            case ' ':case '\t':case '\r':case '\n':
+                                advance_past_space_character();
+                                break;
+                            case ',':
+                            case ']':
+                            {
+                                push_token(resources, token_type(end_index_expression_arg), ec);
+                                if (ec) {return path_expression_type();}
+                                state_stack_.pop_back();
+                                break;
+                            }
+                            default:
+                                ec = jsonpath_errc::expected_comma_or_rbracket;
+                                return path_expression_type();
+                        }
+                        break;
+                    }
+                    default:
+                        ++p_;
+                        ++column_;
+                        break;
+                }
+            }
+
+            if (state_stack_.empty())
+            {
+                ec = jsonpath_errc::syntax_error;
+                return path_expression_type();
+            }
+
+            while (state_stack_.size() > 1)
+            {
+                switch (state_stack_.back())
+                {
+                    case path_state::name_or_lbracket: 
+                        state_stack_.back() = path_state::relative_path;
+                        break;
+                    case path_state::relative_path: 
+                        state_stack_.back() = path_state::identifier_or_function_expr;
+                        state_stack_.emplace_back(path_state::unquoted_string);
+                        break;
+                    case path_state::identifier_or_function_expr:
+                        if (!buffer.empty()) // Can't be quoted string
+                        {
+                            push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                            if (ec) {return path_expression_type();}
+                        }
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::unquoted_string: 
+                        state_stack_.pop_back(); // unquoted_string
+                        break;                    
+                    case path_state::relative_location: 
+                        state_stack_.pop_back();
+                        break;
+                    case path_state::identifier:
+                        if (!buffer.empty()) // Can't be quoted string
+                        {
+                            push_token(resources, token_type(resources.new_selector(identifier_selector<Json,JsonReference>(buffer))), ec);
+                            if (ec) {return path_expression_type();}
+                        }
+                        state_stack_.pop_back(); 
+                        break;
+                    case path_state::parent_operator: 
+                    {
+                        push_token(resources, token_type(resources.new_selector(parent_node_selector<Json,JsonReference>(ancestor_depth))), ec);
+                        if (ec) { return path_expression_type(); }
+                        paths_required = true;
+                        state_stack_.pop_back(); 
+                        break;
+                    }
+                    case path_state::ancestor_depth: 
+                        state_stack_.pop_back(); 
+                        break;
+                    default:
+                        ec = jsonpath_errc::syntax_error;
+                        return path_expression_type();
+                }
+            }
+
+            if (state_stack_.size() > 2)
+            {
+                ec = jsonpath_errc::unexpected_eof;
+                return path_expression_type();
+            }
+
+            //std::cout << "\nTokens\n\n";
+            //for (const auto& tok : output_stack_)
+            //{
+            //    std::cout << tok.to_string() << "\n";
+            //}
+            //std::cout << "\n";
+
+            if (output_stack_.empty() || !operator_stack_.empty())
+            {
+                ec = jsonpath_errc::unexpected_eof;
+                return path_expression_type();
+            }
+
+            return path_expression_type(output_stack_.back().selector_, paths_required);
+        }
+
+        void advance_past_space_character()
+        {
+            switch (*p_)
+            {
+                case ' ':case '\t':
+                    ++p_;
+                    ++column_;
+                    break;
+                case '\r':
+                    if (p_+1 < end_input_ && *(p_+1) == '\n')
+                        ++p_;
+                    ++line_;
+                    column_ = 1;
+                    ++p_;
+                    break;
+                case '\n':
+                    ++line_;
+                    column_ = 1;
+                    ++p_;
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        void unwind_rparen(std::error_code& ec)
+        {
+            auto it = operator_stack_.rbegin();
+            while (it != operator_stack_.rend() && !it->is_lparen())
+            {
+                output_stack_.emplace_back(std::move(*it));
+                ++it;
+            }
+            if (it == operator_stack_.rend())
+            {
+                ec = jsonpath_errc::unbalanced_parentheses;
+                return;
+            }
+            ++it;
+            operator_stack_.erase(it.base(),operator_stack_.end());
+        }
+
+        void push_token(jsoncons::jsonpath::detail::static_resources<value_type,reference>& resources, token_type&& tok, std::error_code& ec)
+        {
+            //std::cout << tok.to_string() << "\n";
+            switch (tok.token_kind())
+            {
+                case jsonpath_token_kind::begin_filter:
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token_type(lparen_arg));
+                    break;
+                case jsonpath_token_kind::end_filter:
+                {
+                    //std::cout << "push_token end_filter 1\n";
+                    //for (const auto& tok2 : output_stack_)
+                    //{
+                    //    std::cout << tok2.to_string() << "\n";
+                    //}
+                    //std::cout << "\n\n";
+                    unwind_rparen(ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    std::vector<token_type> toks;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->token_kind() != jsonpath_token_kind::begin_filter)
+                    {
+                        toks.emplace_back(std::move(*it));
+                        ++it;
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jsonpath_errc::unbalanced_parentheses;
+                        return;
+                    }
+                    std::reverse(toks.begin(), toks.end());
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+
+                    if (!output_stack_.empty() && output_stack_.back().is_path())
+                    {
+                        output_stack_.back().selector_->append_selector(resources.new_selector(filter_selector<Json,JsonReference>(expression_type(std::move(toks)))));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token_type(resources.new_selector(filter_selector<Json,JsonReference>(expression_type(std::move(toks))))));
+                    }
+                    //std::cout << "push_token end_filter 2\n";
+                    //for (const auto& tok2 : output_stack_)
+                    //{
+                    //    std::cout << tok2.to_string() << "\n";
+                    //}
+                    //std::cout << "\n\n";
+                    break;
+                }
+                case jsonpath_token_kind::begin_expression:
+                    //std::cout << "begin_expression\n";
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token_type(lparen_arg));
+                    break;
+                case jsonpath_token_kind::end_index_expression:
+                {
+                    //std::cout << "jsonpath_token_kind::end_index_expression\n";
+                    //for (const auto& t : output_stack_)
+                    //{
+                    //    std::cout << t.to_string() << "\n";
+                    //}
+                    //std::cout << "/jsonpath_token_kind::end_index_expression\n";
+                    unwind_rparen(ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    std::vector<token_type> toks;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->token_kind() != jsonpath_token_kind::begin_expression)
+                    {
+                        toks.emplace_back(std::move(*it));
+                        ++it;
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jsonpath_errc::unbalanced_parentheses;
+                        return;
+                    }
+                    std::reverse(toks.begin(), toks.end());
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+
+                    if (!output_stack_.empty() && output_stack_.back().is_path())
+                    {
+                        output_stack_.back().selector_->append_selector(resources.new_selector(index_expression_selector<Json,JsonReference>(expression_type(std::move(toks)))));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token_type(resources.new_selector(index_expression_selector<Json,JsonReference>(expression_type(std::move(toks))))));
+                    }
+                    break;
+                }
+                case jsonpath_token_kind::end_argument_expression:
+                {
+                    //std::cout << "jsonpath_token_kind::end_index_expression\n";
+                    //for (const auto& t : output_stack_)
+                    //{
+                    //    std::cout << t.to_string() << "\n";
+                    //}
+                    //std::cout << "/jsonpath_token_kind::end_index_expression\n";
+                    unwind_rparen(ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    std::vector<token_type> toks;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->token_kind() != jsonpath_token_kind::begin_expression)
+                    {
+                        toks.emplace_back(std::move(*it));
+                        ++it;
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jsonpath_errc::unbalanced_parentheses;
+                        return;
+                    }
+                    std::reverse(toks.begin(), toks.end());
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+                    output_stack_.emplace_back(token_type(jsoncons::make_unique<expression_type>(std::move(toks))));
+                    break;
+                }
+                case jsonpath_token_kind::selector:
+                {
+                    if (!output_stack_.empty() && output_stack_.back().is_path())
+                    {
+                        output_stack_.back().selector_->append_selector(std::move(tok.selector_));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(std::move(tok));
+                    }
+                    break;
+                }
+                case jsonpath_token_kind::separator:
+                    output_stack_.emplace_back(std::move(tok));
+                    break;
+                case jsonpath_token_kind::begin_union:
+                    output_stack_.emplace_back(std::move(tok));
+                    break;
+                case jsonpath_token_kind::end_union:
+                {
+                    std::vector<selector_type*> expressions;
+                    auto it = output_stack_.rbegin();
+                    while (it != output_stack_.rend() && it->token_kind() != jsonpath_token_kind::begin_union)
+                    {
+                        if (it->token_kind() == jsonpath_token_kind::selector)
+                        {
+                            expressions.emplace_back(std::move(it->selector_));
+                        }
+                        do
+                        {
+                            ++it;
+                        } 
+                        while (it != output_stack_.rend() && it->token_kind() != jsonpath_token_kind::begin_union && it->token_kind() != jsonpath_token_kind::separator);
+                        if (it->token_kind() == jsonpath_token_kind::separator)
+                        {
+                            ++it;
+                        }
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jsonpath_errc::unbalanced_parentheses;
+                        return;
+                    }
+                    std::reverse(expressions.begin(), expressions.end());
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+
+                    if (!output_stack_.empty() && output_stack_.back().is_path())
+                    {
+                        output_stack_.back().selector_->append_selector(resources.new_selector(union_selector<Json,JsonReference>(std::move(expressions))));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token_type(resources.new_selector(union_selector<Json,JsonReference>(std::move(expressions)))));
+                    }
+                    break;
+                }
+                case jsonpath_token_kind::lparen:
+                    operator_stack_.emplace_back(std::move(tok));
+                    break;
+                case jsonpath_token_kind::rparen:
+                {
+                    unwind_rparen(ec);
+                    break;
+                }
+                case jsonpath_token_kind::end_function:
+                {
+                    //std::cout << "jsonpath_token_kind::end_function\n";
+                    unwind_rparen(ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    std::vector<token_type> toks;
+                    auto it = output_stack_.rbegin();
+                    std::size_t arg_count = 0;
+                    while (it != output_stack_.rend() && it->token_kind() != jsonpath_token_kind::function)
+                    {
+                        if (it->token_kind() == jsonpath_token_kind::argument)
+                        {
+                            ++arg_count;
+                        }
+                        toks.emplace_back(std::move(*it));
+                        ++it;
+                    }
+                    if (it == output_stack_.rend())
+                    {
+                        ec = jsonpath_errc::unbalanced_parentheses;
+                        return;
+                    }
+                    std::reverse(toks.begin(), toks.end());
+                    if (it->arity() && arg_count != *(it->arity()))
+                    {
+                        ec = jsonpath_errc::invalid_arity;
+                        return;
+                    }
+                    toks.push_back(std::move(*it));
+                    ++it;
+                    output_stack_.erase(it.base(),output_stack_.end());
+
+                    if (!output_stack_.empty() && output_stack_.back().is_path())
+                    {
+                        output_stack_.back().selector_->append_selector(resources.new_selector(function_selector<Json,JsonReference>(expression_type(std::move(toks)))));
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(token_type(resources.new_selector(function_selector<Json,JsonReference>(std::move(toks)))));
+                    }
+                    break;
+                }
+                case jsonpath_token_kind::literal:
+                    if (!output_stack_.empty() && (output_stack_.back().token_kind() == jsonpath_token_kind::current_node || output_stack_.back().token_kind() == jsonpath_token_kind::root_node))
+                    {
+                        output_stack_.back() = std::move(tok);
+                    }
+                    else
+                    {
+                        output_stack_.emplace_back(std::move(tok));
+                    }
+                    break;
+                case jsonpath_token_kind::function:
+                    output_stack_.emplace_back(std::move(tok));
+                    operator_stack_.emplace_back(token_type(lparen_arg));
+                    break;
+                case jsonpath_token_kind::argument:
+                    output_stack_.emplace_back(std::move(tok));
+                    break;
+                case jsonpath_token_kind::root_node:
+                case jsonpath_token_kind::current_node:
+                    output_stack_.emplace_back(std::move(tok));
+                    break;
+                case jsonpath_token_kind::unary_operator:
+                case jsonpath_token_kind::binary_operator:
+                {
+                    if (operator_stack_.empty() || operator_stack_.back().is_lparen())
+                    {
+                        operator_stack_.emplace_back(std::move(tok));
+                    }
+                    else if (tok.precedence_level() < operator_stack_.back().precedence_level()
+                             || (tok.precedence_level() == operator_stack_.back().precedence_level() && tok.is_right_associative()))
+                    {
+                        operator_stack_.emplace_back(std::move(tok));
+                    }
+                    else
+                    {
+                        auto it = operator_stack_.rbegin();
+                        while (it != operator_stack_.rend() && it->is_operator()
+                               && (tok.precedence_level() > it->precedence_level()
+                             || (tok.precedence_level() == it->precedence_level() && tok.is_right_associative())))
+                        {
+                            output_stack_.emplace_back(std::move(*it));
+                            ++it;
+                        }
+
+                        operator_stack_.erase(it.base(),operator_stack_.end());
+                        operator_stack_.emplace_back(std::move(tok));
+                    }
+                    break;
+                }
+                default:
+                    break;
+            }
+            //std::cout << "  " << "Output Stack\n";
+            //for (auto&& t : output_stack_)
+            //{
+            //    std::cout << t.to_string(2) << "\n";
+            //}
+            //if (!operator_stack_.empty())
+            //{
+            //    std::cout << "  " << "Operator Stack\n";
+            //    for (auto&& t : operator_stack_)
+            //    {
+            //        std::cout << t.to_string(2) << "\n";
+            //    }
+            //}
+        }
+
+        uint32_t append_to_codepoint(uint32_t cp, int c, std::error_code& ec)
+        {
+            cp *= 16;
+            if (c >= '0'  &&  c <= '9')
+            {
+                cp += c - '0';
+            }
+            else if (c >= 'a'  &&  c <= 'f')
+            {
+                cp += c - 'a' + 10;
+            }
+            else if (c >= 'A'  &&  c <= 'F')
+            {
+                cp += c - 'A' + 10;
+            }
+            else
+            {
+                ec = jsonpath_errc::invalid_codepoint;
+            }
+            return cp;
+        }
+    };
+
+    } // namespace detail
+
+    template <class Json,class JsonReference = const Json&>
+    class jsonpath_expression
+    {
+    public:
+        using evaluator_t = typename jsoncons::jsonpath::detail::jsonpath_evaluator<Json, JsonReference>;
+        using char_type = typename evaluator_t::char_type;
+        using string_type = typename evaluator_t::string_type;
+        using string_view_type = typename evaluator_t::string_view_type;
+        using value_type = typename evaluator_t::value_type;
+        using reference = typename evaluator_t::reference;
+        using parameter_type = parameter<Json>;
+        using json_selector_t = typename evaluator_t::path_expression_type;
+        using path_value_pair_type = typename evaluator_t::path_value_pair_type;
+        using json_location_type = typename evaluator_t::json_location_type;
+        using function_type = std::function<value_type(jsoncons::span<const parameter_type>, std::error_code& ec)>;
+    private:
+        jsoncons::jsonpath::detail::static_resources<value_type,reference> static_resources_;
+        json_selector_t expr_;
+    public:
+        jsonpath_expression(jsoncons::jsonpath::detail::static_resources<value_type,reference>&& resources,
+                            json_selector_t&& expr)
+            : static_resources_(std::move(resources)), 
+              expr_(std::move(expr))
+        {
+        }
+
+        jsonpath_expression(jsoncons::jsonpath::detail::static_resources<value_type,reference>&& resources,
+                            json_selector_t&& expr, std::vector<function_type>&& custom_functions)
+            : static_resources_(std::move(resources)), 
+              expr_(std::move(expr), std::move(custom_functions))
+        {
+        }
+
+        template <class BinaryCallback>
+        typename std::enable_if<type_traits::is_binary_function_object<BinaryCallback,const string_type&,reference>::value,void>::type
+        evaluate(reference instance, BinaryCallback callback, result_options options = result_options())
+        {
+            jsoncons::jsonpath::detail::dynamic_resources<Json,reference> resources;
+            auto f = [&callback](const json_location_type& path, reference val)
+            {
+                callback(path.to_string(), val);
+            };
+            expr_.evaluate(resources, instance, resources.root_path_node(), instance, f, options);
+        }
+
+        Json evaluate(reference instance, result_options options = result_options())
+        {
+            if ((options & result_options::path) == result_options::path)
+            {
+                jsoncons::jsonpath::detail::dynamic_resources<Json,reference> resources;
+
+                Json result(json_array_arg);
+                auto callback = [&result](const json_location_type& p, reference)
+                {
+                    result.emplace_back(p.to_string());
+                };
+                expr_.evaluate(resources, instance, resources.root_path_node(), instance, callback, options);
+                return result;
+            }
+            else
+            {
+                jsoncons::jsonpath::detail::dynamic_resources<Json,reference> resources;
+                return expr_.evaluate(resources, instance, resources.current_path_node(), instance, options);
+            }
+        }
+
+        static jsonpath_expression compile(const string_view_type& path)
+        {
+            jsoncons::jsonpath::detail::static_resources<value_type,reference> resources;
+
+            evaluator_t e;
+            json_selector_t expr = e.compile(resources, path);
+            return jsonpath_expression(std::move(resources), std::move(expr));
+        }
+
+        static jsonpath_expression compile(const string_view_type& path, std::error_code& ec)
+        {
+            jsoncons::jsonpath::detail::static_resources<value_type,reference> resources;
+            evaluator_t e;
+            json_selector_t expr = e.compile(resources, path, ec);
+            return jsonpath_expression(std::move(resources), std::move(expr));
+        }
+
+        static jsonpath_expression compile(const string_view_type& path, 
+                                           const custom_functions<Json>& functions)
+        {
+            jsoncons::jsonpath::detail::static_resources<value_type,reference> resources(functions);
+
+            evaluator_t e;
+            json_selector_t expr = e.compile(resources, path);
+            return jsonpath_expression(std::move(resources), std::move(expr));
+        }
+
+        static jsonpath_expression compile(const string_view_type& path, 
+                                           const custom_functions<Json>& functions, 
+                                           std::error_code& ec)
+        {
+            jsoncons::jsonpath::detail::static_resources<value_type,reference> resources(functions);
+            evaluator_t e;
+            json_selector_t expr = e.compile(resources, path, ec);
+            return jsonpath_expression(std::move(resources), std::move(expr));
+        }
+    };
+
+    template <class Json>
+    jsonpath_expression<Json> make_expression(const typename Json::string_view_type& expr, 
+                                              const custom_functions<Json>& functions = custom_functions<Json>())
+    {
+        return jsonpath_expression<Json>::compile(expr, functions);
+    }
+
+    template <class Json>
+    jsonpath_expression<Json> make_expression(const typename Json::string_view_type& expr, std::error_code& ec)
+    {
+        return jsonpath_expression<Json>::compile(expr, ec);
+    }
+
+    template <class Json>
+    jsonpath_expression<Json> make_expression(const typename Json::string_view_type& expr, 
+                                              const custom_functions<Json>& functions, 
+                                              std::error_code& ec)
+    {
+        return jsonpath_expression<Json>::compile(expr, functions, ec);
+    }
+
+} // namespace jsonpath
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jsonpath/jsonpath_selector.hpp b/include/jsoncons_ext/jsonpath/jsonpath_selector.hpp
new file mode 100644
index 0000000..e06d37c
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/jsonpath_selector.hpp
@@ -0,0 +1,1322 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSONPATH_SELECTOR_HPP
+#define JSONCONS_JSONPATH_JSONPATH_SELECTOR_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::is_const
+#include <limits> // std::numeric_limits
+#include <utility> // std::move
+#include <regex>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_error.hpp>
+#include <jsoncons_ext/jsonpath/expression.hpp>
+
+namespace jsoncons { 
+namespace jsonpath {
+namespace detail {
+
+    struct slice
+    {
+        jsoncons::optional<int64_t> start_;
+        jsoncons::optional<int64_t> stop_;
+        int64_t step_;
+
+        slice()
+            : start_(), stop_(), step_(1)
+        {
+        }
+
+        slice(const jsoncons::optional<int64_t>& start, const jsoncons::optional<int64_t>& end, int64_t step) 
+            : start_(start), stop_(end), step_(step)
+        {
+        }
+
+        slice(const slice& other)
+            : start_(other.start_), stop_(other.stop_), step_(other.step_)
+        {
+        }
+
+        slice& operator=(const slice& rhs) 
+        {
+            if (this != &rhs)
+            {
+                if (rhs.start_)
+                {
+                    start_ = rhs.start_;
+                }
+                else
+                {
+                    start_.reset();
+                }
+                if (rhs.stop_)
+                {
+                    stop_ = rhs.stop_;
+                }
+                else
+                {
+                    stop_.reset();
+                }
+                step_ = rhs.step_;
+            }
+            return *this;
+        }
+
+        int64_t get_start(std::size_t size) const
+        {
+            if (start_)
+            {
+                auto len = *start_ >= 0 ? *start_ : (static_cast<int64_t>(size) + *start_);
+                return len <= static_cast<int64_t>(size) ? len : static_cast<int64_t>(size);
+            }
+            else
+            {
+                if (step_ >= 0)
+                {
+                    return 0;
+                }
+                else 
+                {
+                    return static_cast<int64_t>(size);
+                }
+            }
+        }
+
+        int64_t get_stop(std::size_t size) const
+        {
+            if (stop_)
+            {
+                auto len = *stop_ >= 0 ? *stop_ : (static_cast<int64_t>(size) + *stop_);
+                return len <= static_cast<int64_t>(size) ? len : static_cast<int64_t>(size);
+            }
+            else
+            {
+                return step_ >= 0 ? static_cast<int64_t>(size) : -1;
+            }
+        }
+
+        int64_t step() const
+        {
+            return step_; // Allow negative
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class json_array_receiver : public node_receiver<Json,JsonReference>
+    {
+    public:
+        using reference = JsonReference;
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+
+        Json* val;
+
+        json_array_receiver(Json* ptr)
+            : val(ptr)
+        {
+        }
+
+        void add(const json_location_node_type&, reference value) override
+        {
+            val->emplace_back(value);
+        }
+    };
+
+    template <class Json,class JsonReference>
+    struct path_generator
+    {
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+        using string_type = std::basic_string<char_type>;
+
+        static const json_location_node_type& generate(dynamic_resources<Json,JsonReference>& resources,
+                                                       const json_location_node_type& last, 
+                                                       std::size_t index, 
+                                                       result_options options) 
+        {
+            const result_options require_path = result_options::path | result_options::nodups | result_options::sort;
+            if ((options & require_path) != result_options())
+            {
+                return *resources.create_path_node(&last, index);
+            }
+            else
+            {
+                return last;
+            }
+        }
+
+        static const json_location_node_type& generate(dynamic_resources<Json,JsonReference>& resources,
+                                                       const json_location_node_type& last, 
+                                                       const string_type& identifier, 
+                                                       result_options options) 
+        {
+            const result_options require_path = result_options::path | result_options::nodups | result_options::sort;
+            if ((options & require_path) != result_options())
+            {
+                return *resources.create_path_node(&last, identifier);
+            }
+            else
+            {
+                return last;
+            }
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class base_selector : public jsonpath_selector<Json,JsonReference>
+    {
+        using supertype = jsonpath_selector<Json,JsonReference>;
+
+        supertype* tail_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using json_location_type = typename supertype::json_location_type;
+        using node_receiver_type = typename supertype::node_receiver_type;
+        using selector_type = typename supertype::selector_type;
+
+        base_selector()
+            : supertype(true, 11), tail_(nullptr)
+        {
+        }
+
+        base_selector(bool is_path, std::size_t precedence_level)
+            : supertype(is_path, precedence_level), tail_(nullptr)
+        {
+        }
+
+        void append_selector(selector_type* expr) override
+        {
+            if (!tail_)
+            {
+                tail_ = expr;
+            }
+            else
+            {
+                tail_->append_selector(expr);
+            }
+        }
+
+        void tail_select(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current,
+                           node_receiver_type& receiver,
+                           result_options options) const
+        {
+            if (!tail_)
+            {
+                receiver.add(last, current);
+            }
+            else
+            {
+                tail_->select(resources, root, last, current, receiver, options);
+            }
+        }
+
+        reference evaluate_tail(dynamic_resources<Json,JsonReference>& resources,
+                                reference root,
+                                const json_location_node_type& last, 
+                                reference current, 
+                                result_options options,
+                                std::error_code& ec) const
+        {
+            if (!tail_)
+            {
+                return current;
+            }
+            else
+            {
+                return tail_->evaluate(resources, root, last, current, options, ec);
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            if (tail_)
+            {
+                s.append(tail_->to_string(level));
+            }
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class identifier_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+        using path_generator_type = path_generator<Json,JsonReference>;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+        using string_view_type = basic_string_view<char_type>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+    private:
+        string_type identifier_;
+    public:
+
+        identifier_selector(const string_view_type& identifier)
+            : base_selector<Json,JsonReference>(), identifier_(identifier)
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            //std::string buf;
+            //buf.append("identifier selector: ");
+            //unicode_traits::convert(identifier_.data(),identifier_.size(),buf);
+
+            static const char_type length_name[] = {'l', 'e', 'n', 'g', 't', 'h', 0};
+
+            if (current.is_object())
+            {
+                auto it = current.find(identifier_);
+                if (it != current.object_range().end())
+                {
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, identifier_, options),
+                                        it->value(), receiver, options);
+                }
+            }
+            else if (current.is_array())
+            {
+                int64_t n{0};
+                auto r = jsoncons::detail::to_integer_decimal(identifier_.data(), identifier_.size(), n);
+                if (r)
+                {
+                    std::size_t index = (n >= 0) ? static_cast<std::size_t>(n) : static_cast<std::size_t>(static_cast<int64_t>(current.size()) + n);
+                    if (index < current.size())
+                    {
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, index, options),
+                                            current[index], receiver, options);
+                    }
+                }
+                else if (identifier_ == length_name && current.size() > 0)
+                {
+                    pointer ptr = resources.create_json(current.size());
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, identifier_, options), 
+                                        *ptr, 
+                                        receiver, options);
+                }
+            }
+            else if (current.is_string() && identifier_ == length_name)
+            {
+                string_view_type sv = current.as_string_view();
+                std::size_t count = unicode_traits::count_codepoints(sv.data(), sv.size());
+                pointer ptr = resources.create_json(count);
+                this->tail_select(resources, root, 
+                                    path_generator_type::generate(resources, last, identifier_, options), 
+                                    *ptr, receiver, options);
+            }
+            //std::cout << "end identifier_selector\n";
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            static const char_type length_name[] = {'l', 'e', 'n', 'g', 't', 'h', 0};
+
+            if (current.is_object())
+            {
+                auto it = current.find(identifier_);
+                if (it != current.object_range().end())
+                {
+                    return this->evaluate_tail(resources, root, 
+                                               path_generator_type::generate(resources, last, identifier_, options),
+                                              it->value(), options, ec);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else if (current.is_array())
+            {
+                int64_t n{0};
+                auto r = jsoncons::detail::to_integer_decimal(identifier_.data(), identifier_.size(), n);
+                if (r)
+                {
+                    std::size_t index = (n >= 0) ? static_cast<std::size_t>(n) : static_cast<std::size_t>(static_cast<int64_t>(current.size()) + n);
+                    if (index < current.size())
+                    {
+                        return this->evaluate_tail(resources, root, 
+                                                   path_generator_type::generate(resources, last, index, options),
+                                                   current[index], options, ec);
+                    }
+                    else
+                    {
+                        return resources.null_value();
+                    }
+                }
+                else if (identifier_ == length_name && current.size() > 0)
+                {
+                    pointer ptr = resources.create_json(current.size());
+                    return this->evaluate_tail(resources, root, 
+                                               path_generator_type::generate(resources, last, identifier_, options), 
+                                               *ptr, 
+                                               options, ec);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else if (current.is_string() && identifier_ == length_name)
+            {
+                string_view_type sv = current.as_string_view();
+                std::size_t count = unicode_traits::count_codepoints(sv.data(), sv.size());
+                pointer ptr = resources.create_json(count);
+                return this->evaluate_tail(resources, root, 
+                                           path_generator_type::generate(resources, last, identifier_, options), 
+                                           *ptr, options, ec);
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("identifier selector ");
+            unicode_traits::convert(identifier_.data(),identifier_.size(),s);
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+            //s.append("\n");
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class root_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+        using path_generator_type = path_generator<Json,JsonReference>;
+
+        std::size_t id_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        root_selector(std::size_t id)
+            : base_selector<Json,JsonReference>(), id_(id)
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+                this->tail_select(resources, root, last, root, receiver, options);
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            if (resources.is_cached(id_))
+            {
+                return resources.retrieve_from_cache(id_);
+            }
+            else
+            {
+                auto& ref = this->evaluate_tail(resources, root, last, root, options, ec);
+                if (!ec)
+                {
+                    resources.add_to_cache(id_, ref);
+                }
+
+                return ref;
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("root_selector ");
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class current_node_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        current_node_selector()
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            this->tail_select(resources,  
+                                root, last, current, receiver, options);
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            //std::cout << "current_node_selector: " << current << "\n";
+            return this->evaluate_tail(resources,  
+                                root, last, current, options, ec);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("current_node_selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class parent_node_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        int ancestor_depth_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using json_location_type = typename supertype::json_location_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        parent_node_selector(int ancestor_depth)
+        {
+            ancestor_depth_ = ancestor_depth;
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            const json_location_node_type* ancestor = std::addressof(last);
+            int index = 0;
+            while (ancestor != nullptr && index < ancestor_depth_)
+            {
+                ancestor = ancestor->parent();
+                ++index;
+            }
+
+            if (ancestor != nullptr)
+            {
+                json_location_type path(*ancestor);
+                pointer ptr = jsoncons::jsonpath::select(root,path);
+                if (ptr != nullptr)
+                {
+                    this->tail_select(resources, root, path.last(), *ptr, receiver, options);        
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            const json_location_node_type* ancestor = std::addressof(last);
+            int index = 0;
+            while (ancestor != nullptr && index < ancestor_depth_)
+            {
+                ancestor = ancestor->parent();
+                ++index;
+            }
+
+            if (ancestor != nullptr)
+            {
+                json_location_type path(*ancestor);
+                pointer ptr = jsoncons::jsonpath::select(root,path);
+                if (ptr != nullptr)
+                {
+                    return this->evaluate_tail(resources, root, path.last(), *ptr, options, ec);        
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("parent_node_selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class index_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        int64_t index_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        index_selector(int64_t index)
+            : base_selector<Json,JsonReference>(), index_(index)
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                int64_t slen = static_cast<int64_t>(current.size());
+                if (index_ >= 0 && index_ < slen)
+                {
+                    std::size_t i = static_cast<std::size_t>(index_);
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, i, options), 
+                                        current.at(i), receiver, options);
+                }
+                else 
+                {
+                    int64_t index = slen + index_;
+                    if (index >= 0 && index < slen)
+                    {
+                        std::size_t i = static_cast<std::size_t>(index);
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, i, options), 
+                                            current.at(i), receiver, options);
+                    }
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            if (current.is_array())
+            {
+                int64_t slen = static_cast<int64_t>(current.size());
+                if (index_ >= 0 && index_ < slen)
+                {
+                    std::size_t i = static_cast<std::size_t>(index_);
+                    return this->evaluate_tail(resources, root, 
+                                        path_generator_type::generate(resources, last, i, options), 
+                                        current.at(i), options, ec);
+                }
+                else 
+                {
+                    int64_t index = slen + index_;
+                    if (index >= 0 && index < slen)
+                    {
+                        std::size_t i = static_cast<std::size_t>(index);
+                        return this->evaluate_tail(resources, root, 
+                                            path_generator_type::generate(resources, last, i, options), 
+                                            current.at(i), options, ec);
+                    }
+                    else
+                    {
+                        return resources.null_value();
+                    }
+                }
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class wildcard_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        wildcard_selector()
+            : base_selector<Json,JsonReference>()
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                for (std::size_t i = 0; i < current.size(); ++i)
+                {
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, i, options), current[i], 
+                                        receiver, options);
+                }
+            }
+            else if (current.is_object())
+            {
+                for (auto& member : current.object_range())
+                {
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, member.key(), options), 
+                                        member.value(), receiver, options);
+                }
+            }
+            //std::cout << "end wildcard_selector\n";
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources, root, last, current, receiver, options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("wildcard selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class recursive_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        recursive_selector()
+            : base_selector<Json,JsonReference>()
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                this->tail_select(resources, root, last, current, receiver, options);
+                for (std::size_t i = 0; i < current.size(); ++i)
+                {
+                    select(resources, root, 
+                           path_generator_type::generate(resources, last, i, options), current[i], receiver, options);
+                }
+            }
+            else if (current.is_object())
+            {
+                this->tail_select(resources, root, last, current, receiver, options);
+                for (auto& item : current.object_range())
+                {
+                    select(resources, root, 
+                           path_generator_type::generate(resources, last, item.key(), options), item.value(), receiver, options);
+                }
+            }
+            //std::cout << "end wildcard_selector\n";
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources, root, last, current, receiver, options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("wildcard selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class union_selector final : public jsonpath_selector<Json,JsonReference>
+    {
+        using supertype = jsonpath_selector<Json,JsonReference>;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using json_location_type = typename supertype::json_location_type;
+        using path_expression_type = path_expression<Json, JsonReference>;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+        using selector_type = typename supertype::selector_type;
+    private:
+        std::vector<selector_type*> selectors_;
+        selector_type* tail_;
+    public:
+        union_selector(std::vector<selector_type*>&& selectors)
+            : supertype(true, 11), selectors_(std::move(selectors)), tail_(nullptr)
+        {
+        }
+
+        void append_selector(selector_type* tail) override
+        {
+            if (tail_ == nullptr)
+            {
+                tail_ = tail;
+                for (auto& selector : selectors_)
+                {
+                    selector->append_selector(tail);
+                }
+            }
+            else
+            {
+                tail_->append_selector(tail);
+            }
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            for (auto& selector : selectors_)
+            {
+                selector->select(resources, root, last, current, receiver, options);
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources,root,last,current,receiver,options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("union selector ");
+            for (auto& selector : selectors_)
+            {
+                s.append(selector->to_string(level+1));
+                //s.push_back('\n');
+            }
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class filter_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        expression<Json,JsonReference> expr_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        filter_selector(expression<Json,JsonReference>&& expr)
+            : base_selector<Json,JsonReference>(), expr_(std::move(expr))
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                for (std::size_t i = 0; i < current.size(); ++i)
+                {
+                    std::error_code ec;
+                    value_type r = expr_.evaluate(resources, root, current[i], options, ec);
+                    bool t = ec ? false : detail::is_true(r);
+                    if (t)
+                    {
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, i, options), 
+                                            current[i], receiver, options);
+                    }
+                }
+            }
+            else if (current.is_object())
+            {
+                for (auto& member : current.object_range())
+                {
+                    std::error_code ec;
+                    value_type r = expr_.evaluate(resources, root, member.value(), options, ec);
+                    bool t = ec ? false : detail::is_true(r);
+                    if (t)
+                    {
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, member.key(), options), 
+                                            member.value(), receiver, options);
+                    }
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources, root, last, current, receiver, options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("filter selector ");
+            s.append(expr_.to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class index_expression_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        expression<Json,JsonReference> expr_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        index_expression_selector(expression<Json,JsonReference>&& expr)
+            : base_selector<Json,JsonReference>(), expr_(std::move(expr))
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            std::error_code ec;
+            value_type j = expr_.evaluate(resources, root, current, options, ec);
+
+            if (!ec)
+            {
+                if (j.template is<std::size_t>() && current.is_array())
+                {
+                    std::size_t start = j.template as<std::size_t>();
+                    this->tail_select(resources, root, 
+                                      path_generator_type::generate(resources, last, start, options),
+                                      current.at(start), receiver, options);
+                }
+                else if (j.is_string() && current.is_object())
+                {
+                    this->tail_select(resources, root, 
+                                      path_generator_type::generate(resources, last, j.as_string(), options),
+                                      current.at(j.as_string_view()), receiver, options);
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            //std::cout << "index_expression_selector current: " << current << "\n";
+
+            value_type j = expr_.evaluate(resources, root, current, options, ec);
+
+            if (!ec)
+            {
+                if (j.template is<std::size_t>() && current.is_array())
+                {
+                    std::size_t start = j.template as<std::size_t>();
+                    return this->evaluate_tail(resources, root, last, current.at(start), options, ec);
+                }
+                else if (j.is_string() && current.is_object())
+                {
+                    return this->evaluate_tail(resources, root, last, current.at(j.as_string_view()), options, ec);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("bracket expression selector ");
+            s.append(expr_.to_string(level+1));
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class slice_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+        using path_generator_type = path_generator<Json, JsonReference>;
+
+        slice slice_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        slice_selector(const slice& slic)
+            : base_selector<Json,JsonReference>(), slice_(slic) 
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                auto start = slice_.get_start(current.size());
+                auto end = slice_.get_stop(current.size());
+                auto step = slice_.step();
+
+                if (step > 0)
+                {
+                    if (start < 0)
+                    {
+                        start = 0;
+                    }
+                    if (end > static_cast<int64_t>(current.size()))
+                    {
+                        end = current.size();
+                    }
+                    for (int64_t i = start; i < end; i += step)
+                    {
+                        std::size_t j = static_cast<std::size_t>(i);
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, j, options), 
+                                            current[j], receiver, options);
+                    }
+                }
+                else if (step < 0)
+                {
+                    if (start >= static_cast<int64_t>(current.size()))
+                    {
+                        start = static_cast<int64_t>(current.size()) - 1;
+                    }
+                    if (end < -1)
+                    {
+                        end = -1;
+                    }
+                    for (int64_t i = start; i > end; i += step)
+                    {
+                        std::size_t j = static_cast<std::size_t>(i);
+                        if (j < current.size())
+                        {
+                            this->tail_select(resources, root, 
+                                                path_generator_type::generate(resources, last,j,options), current[j], receiver, options);
+                        }
+                    }
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> accum(jptr);
+            select(resources, root, last, current, accum, options);
+            return *jptr;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class function_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        expression<Json,JsonReference> expr_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        function_selector(expression<Json,JsonReference>&& expr)
+            : base_selector<Json,JsonReference>(), expr_(std::move(expr))
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            std::error_code ec;
+            value_type ref = expr_.evaluate(resources, root, current, options, ec);
+            if (!ec)
+            {
+                this->tail_select(resources, root, last, *resources.create_json(std::move(ref)), receiver, options);
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            value_type ref = expr_.evaluate(resources, root, current, options, ec);
+            if (!ec)
+            {
+                return this->evaluate_tail(resources, root, last, *resources.create_json(std::move(ref)), 
+                                    options, ec);
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("function_selector ");
+            s.append(expr_.to_string(level+1));
+
+            return s;
+        }
+    };
+
+} // namespace detail
+} // namespace jsonpath
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jsonpointer/jsonpointer.hpp b/include/jsoncons_ext/jsonpointer/jsonpointer.hpp
new file mode 100644
index 0000000..41e41e2
--- /dev/null
+++ b/include/jsoncons_ext/jsonpointer/jsonpointer.hpp
@@ -0,0 +1,1577 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPOINTER_JSONPOINTER_HPP
+#define JSONCONS_JSONPOINTER_JSONPOINTER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <iostream>
+#include <iterator>
+#include <utility> // std::move
+#include <system_error> // system_error
+#include <type_traits> // std::enable_if, std::true_type
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer_error.hpp>
+#include <jsoncons/detail/write_number.hpp>
+
+namespace jsoncons { namespace jsonpointer {
+
+    namespace detail {
+
+    enum class pointer_state 
+    {
+        start,
+        escaped,
+        delim
+    };
+
+    } // namespace detail
+
+    template <class CharT>
+    std::basic_string<CharT> escape_string(const std::basic_string<CharT>& s)
+    {
+        std::basic_string<CharT> result;
+        for (auto c : s)
+        {
+            switch (c)
+            {
+                case '~':
+                    result.push_back('~');
+                    result.push_back('0');
+                    break;
+                case '/':
+                    result.push_back('~');
+                    result.push_back('1');
+                    break;
+                default:
+                    result.push_back(c);
+                    break;
+            }
+        }
+        return result;
+    }
+
+    // basic_json_pointer
+
+    template <class CharT>
+    class basic_json_pointer
+    {
+    public:
+        // Member types
+        using char_type = CharT;
+        using string_type = std::basic_string<char_type>;
+        using string_view_type = jsoncons::basic_string_view<char_type>;
+        using const_iterator = typename std::vector<string_type>::const_iterator;
+        using iterator = const_iterator;
+        using const_reverse_iterator = typename std::vector<string_type>::const_reverse_iterator;
+        using reverse_iterator = const_reverse_iterator;
+    private:
+        std::vector<string_type> tokens_;
+    public:
+        // Constructors
+        basic_json_pointer()
+        {
+        }
+
+        basic_json_pointer(const std::vector<string_type>& tokens)
+            : tokens_(tokens)
+        {
+        }
+
+        basic_json_pointer(std::vector<string_type>&& tokens)
+            : tokens_(std::move(tokens))
+        {
+        }
+
+        explicit basic_json_pointer(const string_view_type& s)
+        {
+            std::error_code ec;
+            auto jp = parse(s, ec);
+            if (ec)
+            {
+                throw jsonpointer_error(ec);
+            }
+            tokens_ = std::move(jp.tokens_);
+        }
+
+        explicit basic_json_pointer(const string_view_type& s, std::error_code& ec)
+        {
+            auto jp = parse(s, ec);
+            if (!ec)
+            {
+                tokens_ = std::move(jp.tokens_);
+            }
+        }
+
+        basic_json_pointer(const basic_json_pointer&) = default;
+
+        basic_json_pointer(basic_json_pointer&&) = default;
+
+        static basic_json_pointer parse(const string_view_type& input, std::error_code& ec)
+        {
+            std::vector<string_type> tokens;
+            if (input.empty() || (input[0] == '#' && input.size() == 1))
+            {
+                return basic_json_pointer<CharT>();
+            }
+
+            const char_type* p;
+            const char_type* pend;
+            string_type unescaped;
+            if (input[0] == '#') 
+            {
+                unescaped = unescape_uri_string(input, ec);
+                p = unescaped.data() + 1;
+                pend = unescaped.data() + unescaped.size();
+            }
+            else
+            {
+                p = input.data();
+                pend = input.data() + input.size();
+            }
+
+            auto state = jsonpointer::detail::pointer_state::start;
+            string_type buffer;
+
+            while (p < pend)
+            {
+                bool done = false;
+                while (p < pend && !done)
+                {
+                    switch (state)
+                    {
+                        case jsonpointer::detail::pointer_state::start: 
+                            switch (*p)
+                            {
+                                case '/':
+                                    state = jsonpointer::detail::pointer_state::delim;
+                                    break;
+                                default:
+                                    ec = jsonpointer_errc::expected_slash;
+                                    return basic_json_pointer();
+                            };
+                            break;
+                        case jsonpointer::detail::pointer_state::delim: 
+                            switch (*p)
+                            {
+                                case '/':
+                                    done = true;
+                                    break;
+                                case '~':
+                                    state = jsonpointer::detail::pointer_state::escaped;
+                                    break;
+                                default:
+                                    buffer.push_back(*p);
+                                    break;
+                            };
+                            break;
+                        case jsonpointer::detail::pointer_state::escaped: 
+                            switch (*p)
+                            {
+                                case '0':
+                                    buffer.push_back('~');
+                                    state = jsonpointer::detail::pointer_state::delim;
+                                    break;
+                                case '1':
+                                    buffer.push_back('/');
+                                    state = jsonpointer::detail::pointer_state::delim;
+                                    break;
+                                default:
+                                    ec = jsonpointer_errc::expected_0_or_1;
+                                    return basic_json_pointer();
+                            };
+                            break;
+                    }
+                    ++p;
+                }
+                tokens.push_back(buffer);
+                buffer.clear();
+            }
+            if (!buffer.empty())
+            {
+                tokens.push_back(buffer);
+            }
+            return basic_json_pointer(tokens);
+        }
+
+        static string_type escape_uri_string(const string_type& s)
+        {
+            string_type escaped;
+            for (auto ch : s)
+            {
+                switch (ch)
+                {
+                    case '%':
+                        escaped.append(string_type{'%','2','5'});
+                        break;
+                    case '^':
+                        escaped.append(string_type{'%','5','E'});
+                        break;
+                    case '|':
+                        escaped.append(string_type{'%','7','C'});
+                        break;
+                    case '\\':
+                        escaped.append(string_type{'%','5','C'});
+                        break;
+                    case '\"':
+                        escaped.append(string_type{'%','2','2'});
+                        break;
+                    case ' ':
+                        escaped.append(string_type{'%','2','0'});
+                        break;
+                    default:
+                        escaped.push_back(ch);
+                        break;
+                }
+            }
+
+            return escaped;
+        }
+
+        static string_type unescape_uri_string(const string_view_type& s, std::error_code& ec)
+        {
+            if (s.size() < 3)
+            {
+                return string_type(s);
+            }
+            string_type unescaped;
+            std::size_t last = s.size() - 2;
+            std::size_t pos = 0;
+            while (pos < last)
+            {
+                if (s[pos] == '%')
+                {
+                    uint8_t ch;
+                    auto result = jsoncons::detail::to_integer_base16(s.data() + (pos+1), 2, ch);
+                    if (!result)
+                    {
+                        ec = jsonpointer_errc::invalid_uri_escaped_data;
+                        return string_type(s);
+                    }
+                    unescaped.push_back(ch);
+                    pos += 3;
+                }
+                else
+                {
+                    unescaped.push_back(s[pos]);
+                    ++pos;
+                }
+            }
+            while (pos < s.size())
+            {
+                unescaped.push_back(s[pos]);
+                ++pos;
+            }
+            return unescaped;
+        }
+
+        // operator=
+        basic_json_pointer& operator=(const basic_json_pointer&) = default;
+
+        basic_json_pointer& operator=(basic_json_pointer&&) = default;
+
+        // Modifiers
+
+        void clear()
+        {
+            tokens_.clear();
+        }
+
+        basic_json_pointer& operator/=(const string_type& s) 
+        {
+            tokens_.push_back(s);
+            return *this;
+        }
+
+        template <class IntegerType>
+        typename std::enable_if<type_traits::is_integer<IntegerType>::value, basic_json_pointer&>::type
+        operator/=(IntegerType val)
+        {
+            string_type s;
+            jsoncons::detail::from_integer(val, s);
+            tokens_.push_back(s);
+
+            return *this;
+        }
+
+        basic_json_pointer& operator+=(const basic_json_pointer& p)
+        {
+            for (const auto& s : p.tokens_)
+            {
+                tokens_.push_back(s);
+            }
+            return *this;
+        }
+
+        // Accessors
+        bool empty() const
+        {
+          return tokens_.empty();
+        }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+        JSONCONS_DEPRECATED_MSG("Instead, use to_string()")
+        string_type string() const
+        {
+            return to_string();
+        }
+#endif
+        string_type to_string() const
+        {
+            string_type buffer;
+            for (const auto& token : tokens_)
+            {
+                buffer.push_back('/');
+                for (auto c : token)
+                {
+                    switch (c)
+                    {
+                        case '~':
+                            buffer.push_back('~');
+                            buffer.push_back('0');
+                            break;
+                        case '/':
+                            buffer.push_back('~');
+                            buffer.push_back('1');
+                            break;
+                        default:
+                            buffer.push_back(c);
+                            break;
+                    }
+                }
+            }
+            return buffer;
+        }
+
+        string_type to_uri_fragment() const
+        {
+            string_type buffer{'#'};
+            for (const auto& token : tokens_)
+            {
+                buffer.push_back('/');
+                string_type s = escape_uri_string(token);
+                for (auto c : s)
+                {
+                    switch (c)
+                    {
+                        case '~':
+                            buffer.push_back('~');
+                            buffer.push_back('0');
+                            break;
+                        case '/':
+                            buffer.push_back('~');
+                            buffer.push_back('1');
+                            break;
+                        default:
+                            buffer.push_back(c);
+                            break;
+                    }
+                }
+            }
+            return buffer;
+        }
+
+        // Iterators
+        iterator begin() const
+        {
+            return tokens_.begin();
+        }
+        iterator end() const
+        {
+            return tokens_.end();
+        }
+
+        reverse_iterator rbegin() const
+        {
+            return tokens_.rbegin();
+        }
+        reverse_iterator rend() const
+        {
+            return tokens_.rend();
+        }
+
+        // Non-member functions
+        friend basic_json_pointer<CharT> operator/(const basic_json_pointer<CharT>& lhs, const string_type& rhs)
+        {
+            basic_json_pointer<CharT> p(lhs);
+            p /= rhs;
+            return p;
+        }
+
+        friend basic_json_pointer<CharT> operator+( const basic_json_pointer<CharT>& lhs, const basic_json_pointer<CharT>& rhs )
+        {
+            basic_json_pointer<CharT> p(lhs);
+            p += rhs;
+            return p;
+        }
+
+        friend bool operator==( const basic_json_pointer& lhs, const basic_json_pointer& rhs )
+        {
+            return lhs.tokens_ == rhs.okens_;
+        }
+
+        friend bool operator!=( const basic_json_pointer& lhs, const basic_json_pointer& rhs )
+        {
+            return lhs.tokens_ != rhs.tokens_;
+        }
+
+        friend std::basic_ostream<CharT>&
+        operator<<( std::basic_ostream<CharT>& os, const basic_json_pointer<CharT>& p )
+        {
+            os << p.to_string();
+            return os;
+        }
+    };
+
+    template <class CharT,class IntegerType>
+    typename std::enable_if<type_traits::is_integer<IntegerType>::value, basic_json_pointer<CharT>>::type
+    operator/(const basic_json_pointer<CharT>& lhs, IntegerType rhs)
+    {
+        basic_json_pointer<CharT> p(lhs);
+        p /= rhs;
+        return p;
+    }
+
+    using json_pointer = basic_json_pointer<char>;
+    using wjson_pointer = basic_json_pointer<wchar_t>;
+
+    #if !defined(JSONCONS_NO_DEPRECATED)
+    template<class CharT>
+    using basic_address = basic_json_pointer<CharT>;
+    template<class CharT>
+    using basic_json_ptr = basic_json_pointer<CharT>;
+    JSONCONS_DEPRECATED_MSG("Instead, use json_pointer") typedef json_pointer address;
+    JSONCONS_DEPRECATED_MSG("Instead, use json_pointer") typedef json_pointer json_ptr;
+    JSONCONS_DEPRECATED_MSG("Instead, use wjson_pointer") typedef json_pointer wjson_ptr;
+    #endif
+
+    namespace detail {
+
+    template <class Json>
+    const Json* resolve(const Json* current, const typename Json::string_view_type& buffer, std::error_code& ec)
+    {
+        if (current->is_array())
+        {
+            if (buffer.size() == 1 && buffer[0] == '-')
+            {
+                ec = jsonpointer_errc::index_exceeds_array_size;
+                return current;
+            }
+            std::size_t index{0};
+            auto result = jsoncons::detail::to_integer_decimal(buffer.data(), buffer.length(), index);
+            if (!result)
+            {
+                ec = jsonpointer_errc::invalid_index;
+                return current;
+            }
+            if (index >= current->size())
+            {
+                ec = jsonpointer_errc::index_exceeds_array_size;
+                return current;
+            }
+            current = std::addressof(current->at(index));
+        }
+        else if (current->is_object())
+        {
+            if (!current->contains(buffer))
+            {
+                ec = jsonpointer_errc::key_not_found;
+                return current;
+            }
+            current = std::addressof(current->at(buffer));
+        }
+        else
+        {
+            ec = jsonpointer_errc::expected_object_or_array;
+            return current;
+        }
+        return current;
+    }
+
+    template <class Json>
+    Json* resolve(Json* current, const typename Json::string_view_type& buffer, bool create_if_missing, std::error_code& ec)
+    {
+        if (current->is_array())
+        {
+            if (buffer.size() == 1 && buffer[0] == '-')
+            {
+                ec = jsonpointer_errc::index_exceeds_array_size;
+                return current;
+            }
+            std::size_t index{0};
+            auto result = jsoncons::detail::to_integer_decimal(buffer.data(), buffer.length(), index);
+            if (!result)
+            {
+                ec = jsonpointer_errc::invalid_index;
+                return current;
+            }
+            if (index >= current->size())
+            {
+                ec = jsonpointer_errc::index_exceeds_array_size;
+                return current;
+            }
+            current = std::addressof(current->at(index));
+        }
+        else if (current->is_object())
+        {
+            if (!current->contains(buffer))
+            {
+                if (create_if_missing)
+                {
+                    auto r = current->try_emplace(buffer, Json());
+                    current = std::addressof(r.first->value());
+                }
+                else
+                {
+                    ec = jsonpointer_errc::key_not_found;
+                    return current;
+                }
+            }
+            else
+            {
+                current = std::addressof(current->at(buffer));
+            }
+        }
+        else
+        {
+            ec = jsonpointer_errc::expected_object_or_array;
+            return current;
+        }
+        return current;
+    }
+
+    } // namespace detail
+
+    // get
+
+    template<class Json>
+    Json& get(Json& root, 
+              const basic_json_pointer<typename Json::char_type>& location, 
+              bool create_if_missing,
+              std::error_code& ec)
+    {
+        if (location.empty())
+        {
+            return root;
+        }
+
+        Json* current = std::addressof(root);
+        auto it = location.begin();
+        auto end = location.end();
+        while (it != end)
+        {
+            current = jsoncons::jsonpointer::detail::resolve(current, *it, create_if_missing, ec);
+            if (ec)
+                return *current;
+            ++it;
+        }
+        return *current;
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,Json&>::type
+    get(Json& root, 
+        const StringSource& location_str, 
+        bool create_if_missing,
+        std::error_code& ec)
+    {
+        auto jsonptr = basic_json_pointer<typename Json::char_type>::parse(location_str, ec);
+        if (ec)
+        {
+            return root;
+        }
+        return get(root, jsonptr, create_if_missing, ec);
+    }
+
+    template<class Json>
+    const Json& get(const Json& root, 
+                    const basic_json_pointer<typename Json::char_type>& location, 
+                    std::error_code& ec)
+    {
+        if (location.empty())
+        {
+            return root;
+        }
+
+        const Json* current = std::addressof(root);
+        auto it = location.begin();
+        auto end = location.end();
+        while (it != end)
+        {
+            current = jsoncons::jsonpointer::detail::resolve(current, *it, ec);
+            if (ec)
+                return *current;
+            ++it;
+        }
+        return *current;
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,const Json&>::type
+    get(const Json& root, 
+        const StringSource& location_str, 
+        std::error_code& ec)
+    {
+        auto jsonptr = basic_json_pointer<typename Json::char_type>::parse(location_str, ec);
+        if (ec)
+        {
+            return root;
+        }
+        return get(root, jsonptr, ec);
+    }
+
+    template<class Json>
+    Json& get(Json& root, 
+              const basic_json_pointer<typename Json::char_type>& location, 
+              std::error_code& ec)
+    {
+        return get(root, location, false, ec);
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,Json&>::type
+    get(Json& root, 
+        const StringSource& location_str, 
+        std::error_code& ec)
+    {
+        return get(root, location_str, false, ec);
+    }
+
+    template<class Json>
+    Json& get(Json& root, 
+              const basic_json_pointer<typename Json::char_type>& location,
+              bool create_if_missing = false)
+    {
+        std::error_code ec;
+        Json& j = get(root, location, create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+        return j;
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,Json&>::type
+    get(Json& root, 
+              const StringSource& location_str,
+              bool create_if_missing = false)
+    {
+        std::error_code ec;
+        Json& result = get(root, location_str, create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+        return result;
+    }
+
+    template<class Json>
+    const Json& get(const Json& root, const basic_json_pointer<typename Json::char_type>& location)
+    {
+        std::error_code ec;
+        const Json& j = get(root, location, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+        return j;
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,const Json&>::type
+    get(const Json& root, const StringSource& location_str)
+    {
+        std::error_code ec;
+        const Json& j = get(root, location_str, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+        return j;
+    }
+
+    // contains
+
+    template<class Json>
+    bool contains(const Json& root, const basic_json_pointer<typename Json::char_type>& location)
+    {
+        std::error_code ec;
+        get(root, location, ec);
+        return !ec ? true : false;
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,bool>::type
+    contains(const Json& root, const StringSource& location_str)
+    {
+        std::error_code ec;
+        get(root, location_str, ec);
+        return !ec ? true : false;
+    }
+
+    template<class Json,class T>
+    void add(Json& root, 
+             const basic_json_pointer<typename Json::char_type>& location, 
+             T&& value, 
+             bool create_if_missing,
+             std::error_code& ec)
+    {
+        Json* current = std::addressof(root);
+
+        std::basic_string<typename Json::char_type> buffer;
+        auto it = location.begin();
+        auto end = location.end();
+        while (it != end)
+        {
+            buffer = *it;
+            ++it;
+            if (it != end)
+            {
+                current = jsoncons::jsonpointer::detail::resolve(current, buffer, create_if_missing, ec);
+                if (ec)
+                    return;
+            }
+        }
+        if (current->is_array())
+        {
+            if (buffer.size() == 1 && buffer[0] == '-')
+            {
+                current->emplace_back(std::forward<T>(value));
+                current = std::addressof(current->at(current->size()-1));
+            }
+            else
+            {
+                std::size_t index{0};
+                auto result = jsoncons::detail::to_integer_decimal(buffer.data(), buffer.length(), index);
+                if (!result)
+                {
+                    ec = jsonpointer_errc::invalid_index;
+                    return;
+                }
+                if (index > current->size())
+                {
+                    ec = jsonpointer_errc::index_exceeds_array_size;
+                    return;
+                }
+                if (index == current->size())
+                {
+                    current->emplace_back(std::forward<T>(value));
+                    current = std::addressof(current->at(current->size()-1));
+                }
+                else
+                {
+                    auto it2 = current->insert(current->array_range().begin()+index,std::forward<T>(value));
+                    current = std::addressof(*it2);
+                }
+            }
+        }
+        else if (current->is_object())
+        {
+            auto r = current->insert_or_assign(buffer,std::forward<T>(value));
+            current = std::addressof(r.first->value());
+        }
+        else
+        {
+            ec = jsonpointer_errc::expected_object_or_array;
+            return;
+        }
+    }
+
+    // add
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    add(Json& root, 
+             const StringSource& location_str, 
+             T&& value, 
+             bool create_if_missing,
+             std::error_code& ec)
+    {
+        auto jsonptr = basic_json_pointer<typename Json::char_type>::parse(location_str, ec);
+        if (ec)
+        {
+            return;
+        }
+        add(root, jsonptr, std::forward<T>(value), create_if_missing, ec);
+    }
+
+    template<class Json,class T>
+    void add(Json& root, 
+             const basic_json_pointer<typename Json::char_type>& location, 
+             T&& value, 
+             std::error_code& ec)
+    {
+        add(root, location, std::forward<T>(value), false, ec);
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    add(Json& root, 
+             const StringSource& location_str, 
+             T&& value, 
+             std::error_code& ec)
+    {
+        add(root, location_str, std::forward<T>(value), false, ec);
+    }
+
+    template<class Json,class T>
+    void add(Json& root, 
+             const basic_json_pointer<typename Json::char_type>& location, 
+             T&& value,
+             bool create_if_missing = false)
+    {
+        std::error_code ec;
+        add(root, location, std::forward<T>(value), create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    add(Json& root, 
+             const StringSource& location_str, 
+             T&& value,
+             bool create_if_missing = false)
+    {
+        std::error_code ec;
+        add(root, location_str, std::forward<T>(value), create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    // add_if_absent
+
+    template<class Json, class T>
+    void add_if_absent(Json& root, 
+                       const basic_json_pointer<typename Json::char_type>& location, 
+                       T&& value, 
+                       bool create_if_missing,
+                       std::error_code& ec)
+    {
+        Json* current = std::addressof(root);
+
+        std::basic_string<typename Json::char_type> buffer;
+        auto it = location.begin();
+        auto end = location.end();
+
+        while (it != end)
+        {
+            buffer = *it;
+            ++it;
+            if (it != end)
+            {
+                current = jsoncons::jsonpointer::detail::resolve(current, buffer, create_if_missing, ec);
+                if (ec)
+                    return;
+            }
+        }
+        if (current->is_array())
+        {
+            if (buffer.size() == 1 && buffer[0] == '-')
+            {
+                current->emplace_back(std::forward<T>(value));
+                current = std::addressof(current->at(current->size()-1));
+            }
+            else
+            {
+                std::size_t index{0};
+                auto result = jsoncons::detail::to_integer_decimal(buffer.data(), buffer.length(), index);
+                if (!result)
+                {
+                    ec = jsonpointer_errc::invalid_index;
+                    return;
+                }
+                if (index > current->size())
+                {
+                    ec = jsonpointer_errc::index_exceeds_array_size;
+                    return;
+                }
+                if (index == current->size())
+                {
+                    current->emplace_back(std::forward<T>(value));
+                    current = std::addressof(current->at(current->size()-1));
+                }
+                else
+                {
+                    auto it2 = current->insert(current->array_range().begin()+index,std::forward<T>(value));
+                    current = std::addressof(*it2);
+                }
+            }
+        }
+        else if (current->is_object())
+        {
+            if (current->contains(buffer))
+            {
+                ec = jsonpointer_errc::key_already_exists;
+                return;
+            }
+            else
+            {
+                auto r = current->try_emplace(buffer,std::forward<T>(value));
+                current = std::addressof(r.first->value());
+            }
+        }
+        else
+        {
+            ec = jsonpointer_errc::expected_object_or_array;
+            return;
+        }
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    add_if_absent(Json& root, 
+                       const StringSource& location_str, 
+                       T&& value, 
+                       bool create_if_missing,
+                       std::error_code& ec)
+    {
+        auto jsonptr = basic_json_pointer<typename Json::char_type>::parse(location_str, ec);
+        if (ec)
+        {
+            return;
+        }
+        add_if_absent(root, jsonptr, std::forward<T>(value), create_if_missing, ec);
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    add_if_absent(Json& root, 
+                const StringSource& location, 
+                T&& value, 
+                std::error_code& ec)
+    {
+        add_if_absent(root, location, std::forward<T>(value), false, ec);
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    add_if_absent(Json& root, 
+                const StringSource& location_str, 
+                T&& value,
+                bool create_if_missing = false)
+    {
+        std::error_code ec;
+        add_if_absent(root, location_str, std::forward<T>(value), create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    template<class Json, class T>
+    void add_if_absent(Json& root, 
+                       const basic_json_pointer<typename Json::char_type>& location, 
+                       T&& value, 
+                       std::error_code& ec)
+    {
+        add_if_absent(root, location, std::forward<T>(value), false, ec);
+    }
+
+    template<class Json, class T>
+    void add_if_absent(Json& root, 
+                const basic_json_pointer<typename Json::char_type>& location, 
+                T&& value,
+                bool create_if_missing = false)
+    {
+        std::error_code ec;
+        add_if_absent(root, location, std::forward<T>(value), create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    // remove
+
+    template<class Json>
+    void remove(Json& root, const basic_json_pointer<typename Json::char_type>& location, std::error_code& ec)
+    {
+        Json* current = std::addressof(root);
+
+        std::basic_string<typename Json::char_type> buffer;
+        auto it = location.begin();
+        auto end = location.end();
+
+        while (it != end)
+        {
+            buffer = *it;
+            ++it;
+            if (it != end)
+            {
+                current = jsoncons::jsonpointer::detail::resolve(current, buffer, false, ec);
+                if (ec)
+                    return;
+            }
+        }
+        if (current->is_array())
+        {
+            if (buffer.size() == 1 && buffer[0] == '-')
+            {
+                ec = jsonpointer_errc::index_exceeds_array_size;
+                return;
+            }
+            else
+            {
+                std::size_t index{0};
+                auto result = jsoncons::detail::to_integer_decimal(buffer.data(), buffer.length(), index);
+                if (!result)
+                {
+                    ec = jsonpointer_errc::invalid_index;
+                    return;
+                }
+                if (index >= current->size())
+                {
+                    ec = jsonpointer_errc::index_exceeds_array_size;
+                    return;
+                }
+                current->erase(current->array_range().begin()+index);
+            }
+        }
+        else if (current->is_object())
+        {
+            if (!current->contains(buffer))
+            {
+                ec = jsonpointer_errc::key_not_found;
+                return;
+            }
+            else
+            {
+                current->erase(buffer);
+            }
+        }
+        else
+        {
+            ec = jsonpointer_errc::expected_object_or_array;
+            return;
+        }
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    remove(Json& root, const StringSource& location_str, std::error_code& ec)
+    {
+        auto jsonptr = basic_json_pointer<typename Json::char_type>::parse(location_str, ec);
+        if (ec)
+        {
+            return;
+        }
+        remove(root, jsonptr, ec);
+    }
+
+    template<class Json, class StringSource>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    remove(Json& root, const StringSource& location_str)
+    {
+        std::error_code ec;
+        remove(root, location_str, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    template<class Json>
+    void remove(Json& root, const basic_json_pointer<typename Json::char_type>& location)
+    {
+        std::error_code ec;
+        remove(root, location, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    // replace
+
+    template<class Json, class T>
+    void replace(Json& root, 
+                 const basic_json_pointer<typename Json::char_type>& location, 
+                 T&& value, 
+                 bool create_if_missing,
+                 std::error_code& ec)
+    {
+        Json* current = std::addressof(root);
+
+        std::basic_string<typename Json::char_type> buffer;
+        auto it = location.begin();
+        auto end = location.end();
+
+        while (it != end)
+        {
+            buffer = *it;
+            ++it;
+            if (it != end)
+            {
+                current = jsoncons::jsonpointer::detail::resolve(current, buffer, create_if_missing, ec);
+                if (ec)
+                    return;
+            }
+        }
+        if (current->is_array())
+        {
+            if (buffer.size() == 1 && buffer[0] == '-')
+            {
+                ec = jsonpointer_errc::index_exceeds_array_size;
+                return;
+            }
+            else
+            {
+                std::size_t index{};
+                auto result = jsoncons::detail::to_integer_decimal(buffer.data(), buffer.length(), index);
+                if (!result)
+                {
+                    ec = jsonpointer_errc::invalid_index;
+                    return;
+                }
+                if (index >= current->size())
+                {
+                    ec = jsonpointer_errc::index_exceeds_array_size;
+                    return;
+                }
+                current->at(index) = std::forward<T>(value);
+            }
+        }
+        else if (current->is_object())
+        {
+            if (!current->contains(buffer))
+            {
+                if (create_if_missing)
+                {
+                    current->try_emplace(buffer,std::forward<T>(value));
+                }
+                else
+                {
+                    ec = jsonpointer_errc::key_not_found;
+                    return;
+                }
+            }
+            else
+            {
+                auto r = current->insert_or_assign(buffer,std::forward<T>(value));
+                current = std::addressof(r.first->value());
+            }
+        }
+        else
+        {
+            ec = jsonpointer_errc::expected_object_or_array;
+            return;
+        }
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    replace(Json& root, 
+                 const StringSource& location_str, 
+                 T&& value, 
+                 bool create_if_missing,
+                 std::error_code& ec)
+    {
+        auto jsonptr = basic_json_pointer<typename Json::char_type>::parse(location_str, ec);
+        if (ec)
+        {
+            return;
+        }
+        replace(root, jsonptr, std::forward<T>(value), create_if_missing, ec);
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    replace(Json& root, 
+                 const StringSource& location_str, 
+                 T&& value, 
+                 std::error_code& ec)
+    {
+        replace(root, location_str, std::forward<T>(value), false, ec);
+    }
+
+    template<class Json, class StringSource, class T>
+    typename std::enable_if<std::is_convertible<StringSource,jsoncons::basic_string_view<typename Json::char_type>>::value,void>::type
+    replace(Json& root, 
+                 const StringSource& location_str, 
+                 T&& value, 
+                 bool create_if_missing = false)
+    {
+        std::error_code ec;
+        replace(root, location_str, std::forward<T>(value), create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    template<class Json, class T>
+    void replace(Json& root, 
+                 const basic_json_pointer<typename Json::char_type>& location, 
+                 T&& value, 
+                 std::error_code& ec)
+    {
+        replace(root, location, std::forward<T>(value), false, ec);
+    }
+
+    template<class Json, class T>
+    void replace(Json& root, 
+                 const basic_json_pointer<typename Json::char_type>& location, 
+                 T&& value, 
+                 bool create_if_missing = false)
+    {
+        std::error_code ec;
+        replace(root, location, std::forward<T>(value), create_if_missing, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(jsonpointer_error(ec));
+        }
+    }
+
+    template <class String,class Result>
+    typename std::enable_if<std::is_convertible<typename String::value_type,typename Result::value_type>::value>::type
+    escape(const String& s, Result& result)
+    {
+        for (auto c : s)
+        {
+            if (c == '~')
+            {
+                result.push_back('~');
+                result.push_back('0');
+            }
+            else if (c == '/')
+            {
+                result.push_back('~');
+                result.push_back('1');
+            }
+            else
+            {
+                result.push_back(c);
+            }
+        }
+    }
+
+    template <class CharT>
+    std::basic_string<CharT> escape(const jsoncons::basic_string_view<CharT>& s)
+    {
+        std::basic_string<CharT> result;
+
+        for (auto c : s)
+        {
+            if (c == '~')
+            {
+                result.push_back('~');
+                result.push_back('0');
+            }
+            else if (c == '/')
+            {
+                result.push_back('~');
+                result.push_back('1');
+            }
+            else
+            {
+                result.push_back(c);
+            }
+        }
+        return result;
+    }
+
+    // flatten
+
+    template<class Json>
+    void flatten_(const std::basic_string<typename Json::char_type>& parent_key,
+                  const Json& parent_value,
+                  Json& result)
+    {
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+
+        switch (parent_value.type())
+        {
+            case json_type::array_value:
+            {
+                if (parent_value.empty())
+                {
+                    // Flatten empty array to null
+                    //result.try_emplace(parent_key, null_type{});
+                    //result[parent_key] = parent_value;
+                    result.try_emplace(parent_key, parent_value);
+                }
+                else
+                {
+                    for (std::size_t i = 0; i < parent_value.size(); ++i)
+                    {
+                        string_type key(parent_key);
+                        key.push_back('/');
+                        jsoncons::detail::from_integer(i,key);
+                        flatten_(key, parent_value.at(i), result);
+                    }
+                }
+                break;
+            }
+
+            case json_type::object_value:
+            {
+                if (parent_value.empty())
+                {
+                    // Flatten empty object to null
+                    //result.try_emplace(parent_key, null_type{});
+                    //result[parent_key] = parent_value;
+                    result.try_emplace(parent_key, parent_value);
+                }
+                else
+                {
+                    for (const auto& item : parent_value.object_range())
+                    {
+                        string_type key(parent_key);
+                        key.push_back('/');
+                        escape(jsoncons::basic_string_view<char_type>(item.key().data(),item.key().size()), key);
+                        flatten_(key, item.value(), result);
+                    }
+                }
+                break;
+            }
+
+            default:
+            {
+                // add primitive parent_value with its reference string
+                //result[parent_key] = parent_value;
+                result.try_emplace(parent_key, parent_value);
+                break;
+            }
+        }
+    }
+
+    template<class Json>
+    Json flatten(const Json& value)
+    {
+        Json result;
+        std::basic_string<typename Json::char_type> parent_key;
+        flatten_(parent_key, value, result);
+        return result;
+    }
+
+
+    // unflatten
+
+    enum class unflatten_options {none,assume_object = 1
+    #if !defined(JSONCONS_NO_DEPRECATED)
+,object = assume_object
+#endif
+};
+
+    template<class Json>
+    Json safe_unflatten (Json& value)
+    {
+        if (!value.is_object() || value.empty())
+        {
+            return value;
+        }
+        bool safe = true;
+        std::size_t index = 0;
+        for (const auto& item : value.object_range())
+        {
+            std::size_t n;
+            auto r = jsoncons::detail::to_integer_decimal(item.key().data(),item.key().size(), n);
+            if (!r || (index++ != n))
+            {
+                safe = false;
+                break;
+            }
+        }
+
+        if (safe)
+        {
+            Json j(json_array_arg);
+            j.reserve(value.size());
+            for (auto& item : value.object_range())
+            {
+                j.emplace_back(std::move(item.value()));
+            }
+            Json a(json_array_arg);
+            for (auto& item : j.array_range())
+            {
+                a.emplace_back(safe_unflatten (item));
+            }
+            return a;
+        }
+        else
+        {
+            Json o(json_object_arg);
+            for (auto& item : value.object_range())
+            {
+                o.try_emplace(item.key(), safe_unflatten (item.value()));
+            }
+            return o;
+        }
+    }
+
+    template<class Json>
+    jsoncons::optional<Json> try_unflatten_array(const Json& value)
+    {
+        using char_type = typename Json::char_type;
+
+        if (JSONCONS_UNLIKELY(!value.is_object()))
+        {
+            JSONCONS_THROW(jsonpointer_error(jsonpointer_errc::argument_to_unflatten_invalid));
+        }
+        Json result;
+
+        for (const auto& item: value.object_range())
+        {
+            Json* part = &result;
+            basic_json_pointer<char_type> ptr(item.key());
+            std::size_t index = 0;
+            for (auto it = ptr.begin(); it != ptr.end(); )
+            {
+                auto s = *it;
+                size_t n{0};
+                auto r = jsoncons::detail::to_integer_decimal(s.data(), s.size(), n);
+                if (r.ec == jsoncons::detail::to_integer_errc() && (index++ == n))
+                {
+                    if (!part->is_array())
+                    {
+                        *part = Json(json_array_arg);
+                    }
+                    if (++it != ptr.end())
+                    {
+                        if (n+1 > part->size())
+                        {
+                            Json& ref = part->emplace_back();
+                            part = std::addressof(ref);
+                        }
+                        else
+                        {
+                            part = &part->at(n);
+                        }
+                    }
+                    else
+                    {
+                        Json& ref = part->emplace_back(item.value());
+                        part = std::addressof(ref);
+                    }
+                }
+                else if (part->is_object())
+                {
+                    if (++it != ptr.end())
+                    {
+                        auto res = part->try_emplace(s,Json());
+                        part = &(res.first->value());
+                    }
+                    else
+                    {
+                        auto res = part->try_emplace(s, item.value());
+                        part = &(res.first->value());
+                    }
+                }
+                else 
+                {
+                    return jsoncons::optional<Json>();
+                }
+            }
+        }
+
+        return result;
+    }
+
+    template<class Json>
+    Json unflatten_to_object(const Json& value, unflatten_options options = unflatten_options::none)
+    {
+        using char_type = typename Json::char_type;
+
+        if (JSONCONS_UNLIKELY(!value.is_object()))
+        {
+            JSONCONS_THROW(jsonpointer_error(jsonpointer_errc::argument_to_unflatten_invalid));
+        }
+        Json result;
+
+        for (const auto& item: value.object_range())
+        {
+            Json* part = &result;
+            basic_json_pointer<char_type> ptr(item.key());
+            for (auto it = ptr.begin(); it != ptr.end(); )
+            {
+                auto s = *it;
+                if (++it != ptr.end())
+                {
+                    auto res = part->try_emplace(s,Json());
+                    part = &(res.first->value());
+                }
+                else
+                {
+                    auto res = part->try_emplace(s, item.value());
+                    part = &(res.first->value());
+                }
+            }
+        }
+
+        return options == unflatten_options::none ? safe_unflatten (result) : result;
+    }
+
+    template<class Json>
+    Json unflatten(const Json& value, unflatten_options options = unflatten_options::none)
+    {
+        if (options == unflatten_options::none)
+        {
+            jsoncons::optional<Json> j = try_unflatten_array(value);
+            return j ? *j : unflatten_to_object(value,options);
+        }
+        else
+        {
+            return unflatten_to_object(value,options);
+        }
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    template<class Json>
+    JSONCONS_DEPRECATED_MSG("Instead, use add(Json&, const typename Json::string_view_type&, const Json&)")
+    void insert_or_assign(Json& root, const std::basic_string<typename Json::char_type>& location, const Json& value)
+    {
+        add(root, location, value);
+    }
+
+    template<class Json>
+    JSONCONS_DEPRECATED_MSG("Instead, use add(Json&, const typename Json::string_view_type&, const Json&, std::error_code&)")
+    void insert_or_assign(Json& root, const std::basic_string<typename Json::char_type>& location, const Json& value, std::error_code& ec)
+    {
+        add(root, location, value, ec);
+    }
+    template<class Json, class T>
+    void insert(Json& root, 
+                const std::basic_string<typename Json::char_type>& location, 
+                T&& value, 
+                bool create_if_missing,
+                std::error_code& ec)
+    {
+        add_if_absent(root,location,std::forward<T>(value),create_if_missing,ec);
+    }
+
+    template<class Json, class T>
+    void insert(Json& root, 
+                const std::basic_string<typename Json::char_type>& location, 
+                T&& value, 
+                std::error_code& ec)
+    {
+        add_if_absent(root, location, std::forward<T>(value), ec);
+    }
+
+    template<class Json, class T>
+    void insert(Json& root, 
+                const std::basic_string<typename Json::char_type>& location, 
+                T&& value,
+                bool create_if_missing = false)
+    {
+        add_if_absent(root, location, std::forward<T>(value), create_if_missing);
+    }
+#endif
+
+} // namespace jsonpointer
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/jsonpointer/jsonpointer_error.hpp b/include/jsoncons_ext/jsonpointer/jsonpointer_error.hpp
new file mode 100644
index 0000000..a0cfeff
--- /dev/null
+++ b/include/jsoncons_ext/jsonpointer/jsonpointer_error.hpp
@@ -0,0 +1,119 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPOINTER_JSONPOINTER_ERROR_HPP
+#define JSONCONS_JSONPOINTER_JSONPOINTER_ERROR_HPP
+
+#include <jsoncons/json_exception.hpp>
+#include <system_error>
+
+namespace jsoncons { namespace jsonpointer {
+
+class jsonpointer_error : public std::system_error, public virtual json_exception
+{
+public:
+    jsonpointer_error(const std::error_code& ec)
+        : std::system_error(ec)
+    {
+    }
+    jsonpointer_error(const std::error_code& ec, const std::string& what_arg)
+        : std::system_error(ec, what_arg)
+    {
+    }
+    jsonpointer_error(const std::error_code& ec, const char* what_arg)
+        : std::system_error(ec, what_arg)
+    {
+    }
+    jsonpointer_error(const jsonpointer_error& other) = default;
+
+    jsonpointer_error(jsonpointer_error&& other) = default;
+
+    const char* what() const noexcept override
+    {
+        return std::system_error::what();
+    }
+};
+
+enum class jsonpointer_errc 
+{
+    success = 0,
+    expected_slash = 1,
+    index_exceeds_array_size,
+    expected_0_or_1,
+    invalid_index,
+    key_not_found,
+    key_already_exists,
+    expected_object_or_array,
+    end_of_input,
+    unexpected_end_of_input,
+    argument_to_unflatten_invalid,
+    invalid_flattened_key,
+    invalid_uri_escaped_data
+};
+
+class jsonpointer_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/jsonpointer";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<jsonpointer_errc>(ev))
+        {
+            case jsonpointer_errc::expected_slash:
+                return "Expected /";
+            case jsonpointer_errc::index_exceeds_array_size:
+                return "Index exceeds array size";
+            case jsonpointer_errc::expected_0_or_1:
+                return "Expected '0' or '1' after escape character '~'";
+            case jsonpointer_errc::key_not_found:
+                return "Key not found";
+            case jsonpointer_errc::invalid_index:
+                return "Invalid array index";
+            case jsonpointer_errc::key_already_exists:
+                return "Key already exists";
+            case jsonpointer_errc::expected_object_or_array:
+                return "Expected object or array";
+            case jsonpointer_errc::end_of_input:
+                return "Unexpected end of input";
+            case jsonpointer_errc::unexpected_end_of_input:
+                return "Unexpected end of jsonpointer input";
+            case jsonpointer_errc::argument_to_unflatten_invalid:
+                return "Argument to unflatten must be an object";
+            case jsonpointer_errc::invalid_flattened_key:
+                return "Flattened key is invalid";
+            default:
+                return "Unknown jsonpointer error";
+        }
+    }
+};
+
+inline
+const std::error_category& jsonpointer_error_category()
+{
+  static jsonpointer_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(jsonpointer_errc result)
+{
+    return std::error_code(static_cast<int>(result),jsonpointer_error_category());
+}
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::jsonpointer::jsonpointer_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/jsonschema/format_validator.hpp b/include/jsoncons_ext/jsonschema/format_validator.hpp
new file mode 100644
index 0000000..312bf41
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/format_validator.hpp
@@ -0,0 +1,968 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_FORMAT_VALIDATOR_HPP
+#define JSONCONS_JSONSCHEMA_FORMAT_VALIDATOR_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/subschema.hpp>
+#include <cassert>
+#include <set>
+#include <sstream>
+#include <iostream>
+#include <cassert>
+#if defined(JSONCONS_HAS_STD_REGEX)
+#include <regex>
+#endif
+
+namespace jsoncons {
+namespace jsonschema {
+
+    inline
+    bool is_atext( char c)
+    {
+        switch (c)
+        {
+            case '!':
+            case '#':
+            case '$':
+            case '%':
+            case '&':
+            case '\'':
+            case '*':
+            case '+':
+            case '-':
+            case '/':
+            case '=':
+            case '?':
+            case '^':
+            case '_':
+            case '`':
+            case '{':
+            case '|':
+            case '}':
+            case '~':
+                return true;
+            default:
+                return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
+        }
+    }
+
+    inline
+    bool is_dtext( char c)
+    {
+        return (c >= 33 && c <= 90) || (c >= 94 && c <= 126);
+    }
+
+    //  RFC 5322, section 3.4.1
+    inline
+    bool validate_email_rfc5322(const std::string& s)
+    {
+        enum class state_t {local_part,atom,dot_atom,quoted_string,amp,domain};
+
+        state_t state = state_t::local_part;
+        std::size_t part_length = 0;
+
+        for (char c : s)
+        {
+            switch (state)
+            {
+                case state_t::local_part:
+                {
+                    if (is_atext(c))
+                    {
+                        state = state_t::atom;
+                    }
+                    else if (c == '"')
+                    {
+                        state = state_t::quoted_string;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::dot_atom:
+                {
+                    if (is_atext(c))
+                    {
+                        ++part_length;
+                        state = state_t::atom;
+                    }
+                    else
+                        return false;
+                    break;
+                }
+                case state_t::atom:
+                {
+                    switch (c)
+                    {
+                        case '@':
+                            state = state_t::domain;
+                            part_length = 0;
+                            break;
+                        case '.':
+                            state = state_t::dot_atom;
+                            ++part_length;
+                            break;
+                        default:
+                            if (is_atext(c))
+                                ++part_length;
+                            else
+                                return false;
+                            break;
+                    }
+                    break;
+                }
+                case state_t::quoted_string:
+                {
+                    if (c == '\"')
+                    {
+                        state = state_t::amp;
+                    }
+                    else
+                    {
+                        ++part_length;
+                    }
+                    break;
+                }
+                case state_t::amp:
+                {
+                    if (c == '@')
+                    {
+                        state = state_t::domain;
+                        part_length = 0;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::domain:
+                {
+                    if (is_dtext(c))
+                    {
+                        ++part_length;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+            }
+        }
+
+        return state == state_t::domain && part_length > 0;
+    }
+
+    // RFC 2673, Section 3.2
+
+    inline
+    bool validate_ipv6_rfc2373(const std::string& s)
+    {
+        enum class state_t{start,expect_hexdig_or_unspecified,
+                              hexdig, decdig,expect_unspecified, unspecified};
+
+        state_t state = state_t::start;
+
+        std::size_t digit_count = 0;
+        std::size_t piece_count = 0;
+        std::size_t piece_count2 = 0;
+        bool has_unspecified = false;
+        std::size_t dec_value = 0;
+
+        for (std::size_t i = 0; i < s.length(); ++i)
+        {
+            char c = s[i];
+            switch (state)
+            {
+                case state_t::start:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                        case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                        case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':
+                            state = state_t::hexdig;
+                            ++digit_count;
+                            piece_count = 0;
+                            break;
+                        case ':':
+                            if (!has_unspecified)
+                            {
+                                state = state_t::expect_unspecified;
+                            }
+                            else
+                            {
+                                return false;
+                            }
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::expect_hexdig_or_unspecified:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            dec_value = dec_value*10 + static_cast<std::size_t>(c - '0'); // just in case this piece is followed by a dot
+                            state = state_t::hexdig;
+                            ++digit_count;
+                            break;
+                        case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                        case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':
+                            state = state_t::hexdig;
+                            ++digit_count;
+                            break;
+                        case ':':
+                            if (!has_unspecified)
+                            {
+                                has_unspecified = true;
+                                state = state_t::unspecified;
+                            }
+                            else
+                            {
+                                return false;
+                            }
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::expect_unspecified:
+                {
+                    if (c == ':')
+                    {
+                        has_unspecified = true;
+                        state = state_t::unspecified;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::hexdig:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                        case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                        case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':
+                            ++digit_count;
+                            break;
+                        case ':':
+                            if (digit_count <= 4)
+                            {
+                                ++piece_count;
+                                digit_count = 0;
+                                dec_value = 0;
+                                state = state_t::expect_hexdig_or_unspecified;
+                            }
+                            else
+                            {
+                                return false;
+                            }
+                            break;
+                        case '.':
+                            if (piece_count == 6 || has_unspecified)
+                            {
+                                ++piece_count2;
+                                state = state_t::decdig;
+                                dec_value = 0;
+                            }
+                            else
+                            {
+                                return false;
+                            }
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::decdig:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            dec_value = dec_value*10 + static_cast<std::size_t>(c - '0');
+                            ++digit_count;
+                            break;
+                        case '.':
+                            if (dec_value > 0xff)
+                            {
+                                return false;
+                            }
+                            digit_count = 0;
+                            dec_value = 0;
+                            ++piece_count2;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::unspecified:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                        case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                        case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':
+                            state = state_t::hexdig;
+                            ++digit_count;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                default:
+                    return false;
+            }
+        }
+
+        switch (state)
+        {
+            case state_t::unspecified:
+                return piece_count <= 8;
+            case state_t::hexdig:
+                if (digit_count <= 4)
+                {
+                    ++piece_count;
+                    return digit_count > 0 && (piece_count == 8 || (has_unspecified && piece_count <= 8));
+                }
+                else
+                {
+                    return false;
+                }
+            case state_t::decdig:
+                ++piece_count2;
+                if (dec_value > 0xff)
+                {
+                    return false;
+                }
+                return digit_count > 0 && piece_count2 == 4;
+            default:
+                return false;
+        }
+    }
+
+    // RFC 2673, Section 3.2
+
+    inline
+    bool validate_ipv4_rfc2673(const std::string& s)
+    {
+        enum class state_t {expect_indicator_or_dotted_quad,decbyte,
+                              bindig, octdig, hexdig};
+
+        state_t state = state_t::expect_indicator_or_dotted_quad;
+
+        std::size_t digit_count = 0;
+        std::size_t decbyte_count = 0;
+        std::size_t value = 0;
+
+        for (std::size_t i = 0; i < s.length(); ++i)
+        {
+            char c = s[i];
+            switch (state)
+            {
+                case state_t::expect_indicator_or_dotted_quad:
+                {
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                            state = state_t::decbyte;
+                            decbyte_count = 0;
+                            digit_count = 1;
+                            value = 0;
+                            break;
+                        case 'b':
+                            state = state_t::bindig;
+                            digit_count = 0;
+                            break;
+                        case 'o':
+                            state = state_t::octdig;
+                            digit_count = 0;
+                            break;
+                        case 'x':
+                            state = state_t::hexdig;
+                            digit_count = 0;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::bindig:
+                {
+                    if (digit_count >= 256)
+                    {
+                        return false;
+                    }
+                    switch (c)
+                    {
+                        case '0':case '1':
+                            ++digit_count;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::octdig:
+                {
+                    if (digit_count >= 86)
+                    {
+                        return false;
+                    }
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':
+                            ++digit_count;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::hexdig:
+                {
+                    if (digit_count >= 64)
+                    {
+                        return false;
+                    }
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                        case 'A':case 'B':case 'C':case 'D':case 'E':case 'F':
+                        case 'a':case 'b':case 'c':case 'd':case 'e':case 'f':
+                            ++digit_count;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                case state_t::decbyte:
+                {
+                    if (decbyte_count >= 4)
+                    {
+                        return false;
+                    }
+                    switch (c)
+                    {
+                        case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8': case '9':
+                        {
+                            if (digit_count >= 3)
+                            {
+                                return false;
+                            }
+                            ++digit_count;
+                            value = value*10 + static_cast<std::size_t>(c - '0');
+                            if (value > 255)
+                            {
+                                return false;
+                            }
+                            break;
+                        }
+                        case '.':
+                            if (decbyte_count > 3)
+                            {
+                                return false;
+                            }
+                            ++decbyte_count;
+                            digit_count = 0;
+                            value = 0;
+                            break;
+                        default:
+                            return false;
+                    }
+                    break;
+                }
+                default:
+                    return false;
+            }
+        }
+
+        switch (state)
+        {
+            case state_t::decbyte:
+                if (digit_count > 0)
+                {
+                    ++decbyte_count;
+                }
+                else
+                {
+                    return false;
+                }
+                return (decbyte_count == 4) ? true : false;
+            case state_t::bindig:
+                return digit_count > 0 ? true : false;
+            case state_t::octdig:
+                return digit_count > 0 ? true : false;
+            case state_t::hexdig:
+                return digit_count > 0 ? true : false;
+            default:
+                return false;
+        }
+    }
+
+    // RFC 1034, Section 3.1
+    inline
+    bool validate_hostname_rfc1034(const std::string& hostname)
+    {
+        enum class state_t {start_label,expect_letter_or_digit_or_hyphen_or_dot};
+
+        state_t state = state_t::start_label;
+        std::size_t length = hostname.length() - 1;
+        std::size_t label_length = 0;
+
+        for (std::size_t i = 0; i < length; ++i)
+        {
+            char c = hostname[i];
+            switch (state)
+            {
+                case state_t::start_label:
+                {
+                    if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
+                    {
+                        ++label_length;
+                        state = state_t::expect_letter_or_digit_or_hyphen_or_dot;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::expect_letter_or_digit_or_hyphen_or_dot:
+                {
+                    if (c == '.')
+                    {
+                        label_length = 0;
+                        state = state_t::start_label;
+                    }
+                    else if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
+                               (c >= '0' && c < '9') || c == '-'))
+                    {
+                        return false;
+                    }
+                    if (++label_length > 63)
+                    {
+                        return false;
+                    }
+                    break;
+                }
+            }
+        }
+
+        char last = hostname.back();
+        if (!((last >= 'a' && last <= 'z') || (last >= 'A' && last <= 'Z') || (last >= '0' && last < '9')))
+        {
+            return false;
+        }
+        return true;
+    }
+
+    inline
+    bool is_leap_year(std::size_t year)
+    {
+        return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
+    }
+
+    inline
+    std::size_t days_in_month(std::size_t year, std::size_t month)
+    {
+        switch (month)
+        {
+            case 1: return 31;
+            case 2: return is_leap_year(year) ? 29 : 28;
+            case 3: return 31;
+            case 4: return 30;
+            case 5: return 31;
+            case 6: return 30;
+            case 7: return 31;
+            case 8: return 31;
+            case 9: return 30;
+            case 10: return 31;
+            case 11: return 30;
+            case 12: return 31;
+            default:
+                JSONCONS_UNREACHABLE();
+                break;
+        }
+    }
+
+    enum class date_time_type {date_time,date,time};
+    // RFC 3339, Section 5.6
+    inline
+    bool validate_date_time_rfc3339(const std::string& s, date_time_type type)
+    {
+        enum class state_t {fullyear,month,mday,hour,minute,second,secfrac,z,offset_hour,offset_minute};
+
+        std::size_t piece_length = 0;
+        std::size_t year = 0;
+        std::size_t month = 0;
+        std::size_t mday = 0;
+        std::size_t value = 0;
+        state_t state = (type == date_time_type::time) ? state_t::hour : state_t::fullyear;
+
+        for (char c : s)
+        {
+            switch (state)
+            {
+                case state_t::fullyear:
+                {
+                    if (piece_length < 4 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        year = year*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (c == '-' && piece_length == 4)
+                    {
+                        state = state_t::month;
+                        piece_length = 0;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::month:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        month = month*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (c == '-' && piece_length == 2 && (month >=1 && month <= 12))
+                    {
+                        state = state_t::mday;
+                        piece_length = 0;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::mday:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        mday = mday *10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if ((c == 'T' || c == 't') && piece_length == 2 && (mday <= days_in_month(year, month)))
+                    {
+                        piece_length = 0;
+                        state = state_t::hour;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::hour:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        value = value*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (c == ':' && piece_length == 2 && (/*value >=0 && */ value <= 23))
+                    {
+                        state = state_t::minute;
+                        value = 0;
+                        piece_length = 0;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::minute:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        value = value*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (c == ':' && piece_length == 2 && (/*value >=0 && */value <= 59))
+                    {
+                        state = state_t::second;
+                        value = 0;
+                        piece_length = 0;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::second:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        value = value*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (piece_length == 2 && (/*value >=0 && */value <= 60)) // 00-58, 00-59, 00-60 based on leap second rules
+                    {
+                        switch (c)
+                        {
+                            case '.':
+                                value = 0;
+                                state = state_t::secfrac;
+                                break;
+                            case '+':
+                            case '-':
+                                value = 0;
+                                piece_length = 0;
+                                state = state_t::offset_hour;
+                                break;
+                            case 'Z':
+                            case 'z':
+                                state = state_t::z;
+                                break;
+                            default:
+                                return false;
+                        }
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::secfrac:
+                {
+                    if (c >= '0' && c <= '9')
+                    {
+                        value = value*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else
+                    {
+                        switch (c)
+                        {
+                            case '+':
+                            case '-':
+                                value = 0;
+                                piece_length = 0;
+                                state = state_t::offset_hour;
+                                break;
+                            case 'Z':
+                            case 'z':
+                                state = state_t::z;
+                                break;
+                            default:
+                                return false;
+                        }
+                    }
+                    break;
+                }
+                case state_t::offset_hour:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        value = value*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (c == ':' && piece_length == 2 && (/*value >=0 && */value <= 23))
+                    {
+                        value = 0;
+                        piece_length = 0;
+                        state = state_t::offset_minute;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::offset_minute:
+                {
+                    if (piece_length < 2 && (c >= '0' && c <= '9'))
+                    {
+                        piece_length++;
+                        value = value*10 + static_cast<std::size_t>(c - '0');
+                    }
+                    else if (c == ':' && piece_length == 2 && (/*value >=0 && */value <= 59))
+                    {
+                        value = 0;
+                        piece_length = 0;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                    break;
+                }
+                case state_t::z:
+                    return false;
+            }
+        }
+
+        if (type == date_time_type::date)
+        {
+            return state == state_t::mday && piece_length == 2 && (mday >= 1 && mday <= days_in_month(year, month));
+        }
+        else
+        {
+            return state == state_t::offset_minute || state == state_t::z || state == state_t::secfrac;
+        }
+    }
+
+    // format checkers
+    using format_checker = std::function<void(const std::string& absolute_keyword_location,
+                                              const jsonpointer::json_pointer& instance_location, 
+                                              const std::string&, 
+                                              error_reporter& reporter)>;
+
+    inline
+    void rfc3339_date_check(const std::string& absolute_keyword_location,
+                            const jsonpointer::json_pointer& instance_location, 
+                            const std::string& value,
+                            error_reporter& reporter)
+    {
+        if (!validate_date_time_rfc3339(value,date_time_type::date))
+        {
+            reporter.error(validation_output("date", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a RFC 3339 date string"));
+        }
+    }
+
+    inline
+    void rfc3339_time_check(const std::string& absolute_keyword_location,
+                            const jsonpointer::json_pointer& instance_location, 
+                            const std::string &value,
+                            error_reporter& reporter)
+    {
+        if (!validate_date_time_rfc3339(value, date_time_type::time))        
+        {
+            reporter.error(validation_output("time", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a RFC 3339 time string"));
+        }
+    }
+
+    inline
+    void rfc3339_date_time_check(const std::string& absolute_keyword_location,
+                                 const jsonpointer::json_pointer& instance_location, 
+                                 const std::string &value,
+                                 error_reporter& reporter)
+    {
+        if (!validate_date_time_rfc3339(value, date_time_type::date_time))        
+        {
+            reporter.error(validation_output("date-time",  
+                                             absolute_keyword_location,
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a RFC 3339 date-time string"));
+        }
+    }
+
+    inline
+    void email_check(const std::string& absolute_keyword_location,
+                     const jsonpointer::json_pointer& instance_location, 
+                     const std::string& value,
+                     error_reporter& reporter) 
+    {
+        if (!validate_email_rfc5322(value))        
+        {
+            reporter.error(validation_output("email", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a valid email address as defined by RFC 5322"));
+        }
+    } 
+
+    inline
+    void hostname_check(const std::string& absolute_keyword_location,
+                        const jsonpointer::json_pointer& instance_location, 
+                        const std::string& value,
+                        error_reporter& reporter) 
+    {
+        if (!validate_hostname_rfc1034(value))
+        {
+            reporter.error(validation_output("hostname", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a valid hostname as defined by RFC 3986 Appendix A"));
+        }
+    } 
+
+    inline
+    void ipv4_check(const std::string& absolute_keyword_location,
+                    const jsonpointer::json_pointer& instance_location, 
+                    const std::string& value,
+                    error_reporter& reporter) 
+    {
+        if (!validate_ipv4_rfc2673(value))
+        {
+            reporter.error(validation_output("ipv4", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a valid IPv4 address as defined by RFC 2673"));
+        }
+    } 
+
+    inline
+    void ipv6_check(const std::string& absolute_keyword_location,
+                    const jsonpointer::json_pointer& instance_location, 
+                    const std::string& value,
+                    error_reporter& reporter) 
+    {
+        if (!validate_ipv6_rfc2373(value))
+        {
+            reporter.error(validation_output("ipv6", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a valid IPv6 address as defined by RFC 2373"));
+        }
+    } 
+
+    inline
+    void regex_check(const std::string& absolute_keyword_location,
+                     const jsonpointer::json_pointer& instance_location, 
+                     const std::string& value,
+                     error_reporter& reporter) 
+    {
+#if defined(JSONCONS_HAS_STD_REGEX)
+        try 
+        {
+            std::regex re(value, std::regex::ECMAScript);
+        } 
+        catch (const std::exception& e) 
+        {
+            reporter.error(validation_output("pattern", 
+                                             absolute_keyword_location, 
+                                             instance_location.to_uri_fragment(), 
+                                             "\"" + value + "\" is not a valid ECMAScript regular expression. " + e.what()));
+        }
+#endif
+    } 
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_FORMAT_CHECKERS_HPP
diff --git a/include/jsoncons_ext/jsonschema/json_validator.hpp b/include/jsoncons_ext/jsonschema/json_validator.hpp
new file mode 100644
index 0000000..87bec58
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/json_validator.hpp
@@ -0,0 +1,120 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_JSON_VALIDATOR_HPP
+#define JSONCONS_JSONSCHEMA_JSON_VALIDATOR_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/keyword_validator_factory.hpp>
+#include <cassert>
+#include <set>
+#include <sstream>
+#include <iostream>
+#include <cassert>
+#include <functional>
+
+namespace jsoncons {
+namespace jsonschema {
+
+    class throwing_error_reporter : public error_reporter
+    {
+        void do_error(const validation_output& o) override
+        {
+            JSONCONS_THROW(validation_error(o.message()));
+        }
+    };
+
+    class fail_early_reporter : public error_reporter
+    {
+        void do_error(const validation_output&) override
+        {
+        }
+    public:
+        fail_early_reporter()
+            : error_reporter(true)
+        {
+        }
+    };
+
+    using error_reporter_t = std::function<void(const validation_output& o)>;
+
+    struct error_reporter_adaptor : public error_reporter
+    {
+        error_reporter_t reporter_;
+
+        error_reporter_adaptor(const error_reporter_t& reporter)
+            : reporter_(reporter)
+        {
+        }
+    private:
+        void do_error(const validation_output& e) override
+        {
+            reporter_(e);
+        }
+    };
+
+    template <class Json>
+    class json_validator
+    {
+        std::shared_ptr<json_schema<Json>> root_;
+
+    public:
+        json_validator(std::shared_ptr<json_schema<Json>> root)
+            : root_(root)
+        {
+        }
+
+        json_validator(json_validator &&) = default;
+        json_validator &operator=(json_validator &&) = default;
+
+        json_validator(json_validator const &) = delete;
+        json_validator &operator=(json_validator const &) = delete;
+
+        ~json_validator() = default;
+
+        // Validate input JSON against a JSON Schema with a default throwing error reporter
+        Json validate(const Json& instance) const
+        {
+            throwing_error_reporter reporter;
+            jsonpointer::json_pointer instance_location("#");
+            Json patch(json_array_arg);
+
+            root_->validate(instance, instance_location, reporter, patch);
+            return patch;
+        }
+
+        // Validate input JSON against a JSON Schema 
+        bool is_valid(const Json& instance) const
+        {
+            fail_early_reporter reporter;
+            jsonpointer::json_pointer instance_location("#");
+            Json patch(json_array_arg);
+
+            root_->validate(instance, instance_location, reporter, patch);
+            return reporter.error_count() == 0;
+        }
+
+        // Validate input JSON against a JSON Schema with a provided error reporter
+        template <class Reporter>
+        typename std::enable_if<type_traits::is_unary_function_object_exact<Reporter,void,validation_output>::value,Json>::type
+        validate(const Json& instance, const Reporter& reporter) const
+        {
+            jsonpointer::json_pointer instance_location("#");
+            Json patch(json_array_arg);
+
+            error_reporter_adaptor adaptor(reporter);
+            root_->validate(instance, instance_location, adaptor, patch);
+            return patch;
+        }
+    };
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_JSON_VALIDATOR_HPP
diff --git a/include/jsoncons_ext/jsonschema/jsonschema.hpp b/include/jsoncons_ext/jsonschema/jsonschema.hpp
new file mode 100644
index 0000000..e2c4210
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/jsonschema.hpp
@@ -0,0 +1,13 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_JSONSCHEMA_HPP
+#define JSONCONS_JSONSCHEMA_JSONSCHEMA_HPP
+
+#include <jsoncons_ext/jsonschema/keyword_validator.hpp>
+#include <jsoncons_ext/jsonschema/json_validator.hpp>
+
+#endif // JSONCONS_JSONSCHEMA_JSONSCHEMA_HPP
diff --git a/include/jsoncons_ext/jsonschema/jsonschema_error.hpp b/include/jsoncons_ext/jsonschema/jsonschema_error.hpp
new file mode 100644
index 0000000..7cb1061
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/jsonschema_error.hpp
@@ -0,0 +1,105 @@
+/// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_JSONSCHEMA_ERROR_HPP
+#define JSONCONS_JSONSCHEMA_JSONSCHEMA_ERROR_HPP
+
+#include <jsoncons/json_exception.hpp>
+#include <system_error>
+
+namespace jsoncons {
+namespace jsonschema {
+
+    class schema_error : public std::runtime_error, public virtual json_exception
+    {
+    public:
+        schema_error(const std::string& message)
+            : std::runtime_error(message)
+        {
+        }
+
+        const char* what() const noexcept override
+        {
+            return std::runtime_error::what();
+        }  
+    };
+
+    class validation_error : public std::runtime_error, public virtual json_exception
+    {
+    public:
+        validation_error(const std::string& message)
+            : std::runtime_error(message)
+        {
+        }
+
+        const char* what() const noexcept override
+        {
+            return std::runtime_error::what();
+        }  
+    };
+
+    class validation_output 
+    {
+        std::string keyword_;
+        std::string absolute_keyword_location_;
+        std::string instance_location_;
+        std::string message_;
+        std::vector<validation_output> nested_errors_;
+    public:
+        validation_output(std::string keyword,
+                          std::string absolute_keyword_location,
+                          std::string instance_location,
+                          std::string message)
+            : keyword_(std::move(keyword)), 
+              absolute_keyword_location_(std::move(absolute_keyword_location)),
+              instance_location_(std::move(instance_location)),
+              message_(std::move(message))
+        {
+        }
+
+        validation_output(const std::string& keyword,
+                          const std::string& absolute_keyword_location,
+                          const std::string& instance_location,
+                          const std::string& message,
+                          const std::vector<validation_output>& nested_errors)
+            : keyword_(keyword),
+              absolute_keyword_location_(absolute_keyword_location),
+              instance_location_(instance_location), 
+              message_(message),
+              nested_errors_(nested_errors)
+        {
+        }
+
+        const std::string& instance_location() const
+        {
+            return instance_location_;
+        }
+
+        const std::string& message() const
+        {
+            return message_;
+        }
+
+        const std::string& absolute_keyword_location() const
+        {
+            return absolute_keyword_location_;
+        }
+
+        const std::string& keyword() const
+        {
+            return keyword_;
+        }
+
+        const std::vector<validation_output>& nested_errors() const
+        {
+            return nested_errors_;
+        }
+    };
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_JSONSCHEMA_ERROR_HPP
diff --git a/include/jsoncons_ext/jsonschema/jsonschema_version.hpp b/include/jsoncons_ext/jsonschema/jsonschema_version.hpp
new file mode 100644
index 0000000..bf0afff
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/jsonschema_version.hpp
@@ -0,0 +1,18 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_JSONSCHEMA_VERSION_HPP
+#define JSONCONS_JSONSCHEMA_JSONSCHEMA_VERSION_HPP
+
+#include <jsoncons/json.hpp>
+
+namespace jsoncons {
+namespace jsonschema {
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_JSONSCHEMA_VERSION_HPP
diff --git a/include/jsoncons_ext/jsonschema/keyword_validator.hpp b/include/jsoncons_ext/jsonschema/keyword_validator.hpp
new file mode 100644
index 0000000..249c7d0
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/keyword_validator.hpp
@@ -0,0 +1,1745 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_KEYWORD_VALIDATOR_HPP
+#define JSONCONS_JSONSCHEMA_KEYWORD_VALIDATOR_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/subschema.hpp>
+#include <jsoncons_ext/jsonschema/format_validator.hpp>
+#include <cassert>
+#include <set>
+#include <sstream>
+#include <iostream>
+#include <cassert>
+#if defined(JSONCONS_HAS_STD_REGEX)
+#include <regex>
+#endif
+
+namespace jsoncons {
+namespace jsonschema {
+
+    template <class Json>
+    class abstract_keyword_validator_factory
+    {
+    public:
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        virtual ~abstract_keyword_validator_factory() = default;
+
+        virtual validator_pointer make_keyword_validator(const Json& schema,
+                                                         const std::vector<schema_location>& uris,
+                                                         const std::vector<std::string>& keys) = 0;
+        virtual validator_pointer make_required_validator(const std::vector<schema_location>& uris,
+                                                          const std::vector<std::string>& items) = 0;
+
+        virtual validator_pointer make_null_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_true_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_false_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_object_validator(const Json& sch, 
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_array_validator(const Json& sch,
+                                                       const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_string_validator(const Json& sch,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_boolean_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_integer_validator(const Json& sch, 
+                                                         const std::vector<schema_location>& uris, 
+                                                         std::set<std::string>& keywords) = 0;
+
+        virtual validator_pointer make_number_validator(const Json& sch, 
+                                                        const std::vector<schema_location>& uris, 
+                                                        std::set<std::string>& keywords) = 0;
+
+        virtual validator_pointer make_not_validator(const Json& schema,
+                                                     const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_all_of_validator(const Json& schema,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_any_of_validator(const Json& schema,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_one_of_validator(const Json& schema,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_type_validator(const Json& schema,
+                                                      const std::vector<schema_location>& uris) = 0;
+    };
+
+    struct collecting_error_reporter : public error_reporter
+    {
+        std::vector<validation_output> errors;
+
+    private:
+        void do_error(const validation_output& o) override
+        {
+            errors.push_back(o);
+        }
+    };
+
+    // string keyword_validator
+
+    inline
+    std::string make_absolute_keyword_location(const std::vector<schema_location>& uris,
+                                               const std::string& keyword)
+    {
+        for (auto it = uris.rbegin(); it != uris.rend(); ++it)
+        {
+            if (!it->has_identifier() && it->is_absolute())
+            {
+                return it->append(keyword).string();
+            }
+        }
+        return "";
+    }
+
+    template <class Json>
+    class string_validator : public keyword_validator<Json>
+    {
+        jsoncons::optional<std::size_t> max_length_;
+        std::string max_length_location_;
+        jsoncons::optional<std::size_t> min_length_;
+        std::string min_length_location_;
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+        jsoncons::optional<std::regex> pattern_;
+        std::string pattern_string_;
+        std::string pattern_location_;
+    #endif
+
+        format_checker format_check_;
+        std::string format_location_;
+
+        jsoncons::optional<std::string> content_encoding_;
+        std::string content_encoding_location_;
+        jsoncons::optional<std::string> content_media_type_;
+        std::string content_media_type_location_;
+
+    public:
+        string_validator(const Json& sch, const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), max_length_(), min_length_(), 
+    #if defined(JSONCONS_HAS_STD_REGEX)
+              pattern_(),
+    #endif
+              content_encoding_(), content_media_type_()
+        {
+            auto it = sch.find("maxLength");
+            if (it != sch.object_range().end()) 
+            {
+                max_length_ = it->value().template as<std::size_t>();
+                max_length_location_ = make_absolute_keyword_location(uris, "maxLength");
+            }
+
+            it = sch.find("minLength");
+            if (it != sch.object_range().end()) 
+            {
+                min_length_ = it->value().template as<std::size_t>();
+                min_length_location_ = make_absolute_keyword_location(uris, "minLength");
+            }
+
+            it = sch.find("contentEncoding");
+            if (it != sch.object_range().end()) 
+            {
+                content_encoding_ = it->value().template as<std::string>();
+                content_encoding_location_ = make_absolute_keyword_location(uris, "contentEncoding");
+                // If "contentEncoding" is set to "binary", a Json value
+                // of type json_type::byte_string_value is accepted.
+            }
+
+            it = sch.find("contentMediaType");
+            if (it != sch.object_range().end()) 
+            {
+                content_media_type_ = it->value().template as<std::string>();
+                content_media_type_location_ = make_absolute_keyword_location(uris, "contentMediaType");
+            }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+            it = sch.find("pattern");
+            if (it != sch.object_range().end()) 
+            {
+                pattern_string_ = it->value().template as<std::string>();
+                pattern_ = std::regex(it->value().template as<std::string>(),std::regex::ECMAScript);
+                pattern_location_ = make_absolute_keyword_location(uris, "pattern");
+            }
+    #endif
+
+            it = sch.find("format");
+            if (it != sch.object_range().end()) 
+            {
+                format_location_ = make_absolute_keyword_location(uris, "format");
+                std::string format = it->value().template as<std::string>();
+                if (format == "date-time")
+                {
+                    format_check_ = rfc3339_date_time_check;
+                }
+                else if (format == "date") 
+                {
+                    format_check_ = rfc3339_date_check;
+                } 
+                else if (format == "time") 
+                {
+                    format_check_ = rfc3339_time_check;
+                } 
+                else if (format == "email") 
+                {
+                    format_check_ = email_check;
+                } 
+                else if (format == "hostname") 
+                {
+                    format_check_ = hostname_check;
+                } 
+                else if (format == "ipv4") 
+                {
+                    format_check_ = ipv4_check;
+                } 
+                else if (format == "ipv6") 
+                {
+                    format_check_ = ipv6_check;
+                } 
+                else if (format == "regex") 
+                {
+                    format_check_ = regex_check;
+                } 
+                else
+                {
+                    // Not supported - ignore
+                }
+            }
+        }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter,
+                         Json&) const override
+        {
+            std::string content;
+            if (content_encoding_)
+            {
+                if (*content_encoding_ == "base64")
+                {
+                    auto s = instance.template as<jsoncons::string_view>();
+                    auto retval = jsoncons::decode_base64(s.begin(), s.end(), content);
+                    if (retval.ec != jsoncons::conv_errc::success)
+                    {
+                        reporter.error(validation_output("contentEncoding", 
+                                                         content_encoding_location_, 
+                                                         instance_location.to_uri_fragment(), 
+                                                         "Content is not a base64 string"));
+                        if (reporter.fail_early())
+                        {
+                            return;
+                        }
+                    }
+                }
+                else if (!content_encoding_->empty())
+                {
+                    reporter.error(validation_output("contentEncoding", 
+                                                     content_encoding_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "unable to check for contentEncoding '" + *content_encoding_ + "'"));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+            else
+            {
+                content = instance.template as<std::string>();
+            }
+
+            if (content_media_type_) 
+            {
+                if (content_media_type_ == "application/Json")
+                {
+                    json_string_reader reader(content);
+                    std::error_code ec;
+                    reader.read(ec);
+
+                    if (ec)
+                    {
+                        reporter.error(validation_output("contentMediaType", 
+                                                         content_media_type_location_, 
+                                                         instance_location.to_uri_fragment(), 
+                                                         std::string("Content is not JSON: ") + ec.message()));
+                    }
+                }
+            } 
+            else if (instance.type() == json_type::byte_string_value) 
+            {
+                reporter.error(validation_output("contentMediaType", 
+                                                 content_media_type_location_, 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Expected string, but is byte string"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (instance.type() != json_type::string_value) 
+            {
+                return; 
+            }
+
+            if (min_length_) 
+            {
+                std::size_t length = unicode_traits::count_codepoints(content.data(), content.size());
+                if (length < *min_length_) 
+                {
+                    reporter.error(validation_output("minLength", 
+                                                     min_length_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::string("Expected minLength: ") + std::to_string(*min_length_)
+                                              + ", actual: " + std::to_string(length)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (max_length_) 
+            {
+                std::size_t length = unicode_traits::count_codepoints(content.data(), content.size());
+                if (length > *max_length_)
+                {
+                    reporter.error(validation_output("maxLength", 
+                                                     max_length_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::string("Expected maxLength: ") + std::to_string(*max_length_)
+                        + ", actual: " + std::to_string(length)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+            if (pattern_)
+            {
+                if (!std::regex_search(content, *pattern_))
+                {
+                    std::string message("String \"");
+                    message.append(instance.template as<std::string>());
+                    message.append("\" does not match pattern \"");
+                    message.append(pattern_string_);
+                    message.append("\"");
+                    reporter.error(validation_output("pattern", 
+                                                     pattern_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::move(message)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+    #endif
+
+            if (format_check_ != nullptr) 
+            {
+                format_check_(format_location_, instance_location, content, reporter);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+        }
+    };
+
+    // not_validator
+
+    template <class Json>
+    class not_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        validator_pointer rule_;
+
+    public:
+        not_validator(abstract_keyword_validator_factory<Json>* builder,
+                 const Json& sch,
+                 const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+            rule_ = builder->make_keyword_validator(sch, uris, {"not"});
+        }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const final
+        {
+            collecting_error_reporter local_reporter;
+            rule_->validate(instance, instance_location, local_reporter, patch);
+
+            if (local_reporter.errors.empty())
+            {
+                reporter.error(validation_output("not", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance must not be valid against schema"));
+            }
+        }
+
+        jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer& instance_location, 
+                                                   const Json& instance, 
+                                                   error_reporter& reporter) const override
+        {
+            return rule_->get_default_value(instance_location, instance, reporter);
+        }
+    };
+
+    template <class Json>
+    struct all_of_criterion
+    {
+        static const std::string& key()
+        {
+            static const std::string k("allOf");
+            return k;
+        }
+
+        static bool is_complete(const Json&, 
+                                const jsonpointer::json_pointer& instance_location, 
+                                error_reporter& reporter, 
+                                const collecting_error_reporter& local_reporter, 
+                                std::size_t)
+        {
+            if (!local_reporter.errors.empty())
+                reporter.error(validation_output("allOf", 
+                                                 "",
+                                                 instance_location.to_uri_fragment(), 
+                                                 "At least one schema failed to match, but all are required to match. ", 
+                                                 local_reporter.errors));
+            return !local_reporter.errors.empty();
+        }
+    };
+
+    template <class Json>
+    struct any_of_criterion
+    {
+        static const std::string& key()
+        {
+            static const std::string k("anyOf");
+            return k;
+        }
+
+        static bool is_complete(const Json&, 
+                                const jsonpointer::json_pointer&, 
+                                error_reporter&, 
+                                const collecting_error_reporter&, 
+                                std::size_t count)
+        {
+            return count == 1;
+        }
+    };
+
+    template <class Json>
+    struct one_of_criterion
+    {
+        static const std::string& key()
+        {
+            static const std::string k("oneOf");
+            return k;
+        }
+
+        static bool is_complete(const Json&, 
+                                const jsonpointer::json_pointer& instance_location, 
+                                error_reporter& reporter, 
+                                const collecting_error_reporter&, 
+                                std::size_t count)
+        {
+            if (count > 1)
+            {
+                std::string message(std::to_string(count));
+                message.append(" subschemas matched, but exactly one is required to match");
+                reporter.error(validation_output("oneOf", 
+                                                 "", 
+                                                 instance_location.to_uri_fragment(), 
+                                                 std::move(message)));
+            }
+            return count > 1;
+        }
+    };
+
+    template <class Json,class Criterion>
+    class combining_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        std::vector<validator_pointer> subschemas_;
+
+    public:
+        combining_validator(abstract_keyword_validator_factory<Json>* builder,
+                            const Json& sch,
+                            const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+            size_t c = 0;
+            for (const auto& subsch : sch.array_range())
+            {
+                subschemas_.push_back(builder->make_keyword_validator(subsch, uris, {Criterion::key(), std::to_string(c++)}));
+            }
+
+            // Validate value of allOf, anyOf, and oneOf "MUST be a non-empty array"
+        }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const final
+        {
+            size_t count = 0;
+
+            collecting_error_reporter local_reporter;
+            for (auto& s : subschemas_) 
+            {
+                std::size_t mark = local_reporter.errors.size();
+                s->validate(instance, instance_location, local_reporter, patch);
+                if (mark == local_reporter.errors.size())
+                    count++;
+
+                if (Criterion::is_complete(instance, instance_location, reporter, local_reporter, count))
+                    return;
+            }
+
+            if (count == 0)
+            {
+                reporter.error(validation_output("combined", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "No schema matched, but one of them is required to match", 
+                                                 local_reporter.errors));
+            }
+        }
+    };
+
+    template <class T, class Json>
+    T get_number(const Json& val, const string_view& keyword) 
+    {
+        if (!val.is_number())
+        {
+            std::string message(keyword);
+            message.append(" must be a number value");
+            JSONCONS_THROW(schema_error(message));
+        }
+        return val.template as<T>();
+    }
+
+    template <class Json,class T>
+    class numeric_validator_base : public keyword_validator<Json>
+    {
+        jsoncons::optional<T> maximum_;
+        std::string absolute_maximum_location_;
+        jsoncons::optional<T> minimum_;
+        std::string absolute_minimum_location_;
+        jsoncons::optional<T> exclusive_maximum_;
+        std::string absolute_exclusive_maximum_location_;
+        jsoncons::optional<T> exclusive_minimum_;
+        std::string absolute_exclusive_minimum_location_;
+        jsoncons::optional<double> multiple_of_;
+        std::string absolute_multiple_of_location_;
+
+    public:
+        numeric_validator_base(const Json& sch, 
+                    const std::vector<schema_location>& uris, 
+                    std::set<std::string>& keywords)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), 
+              maximum_(), minimum_(),exclusive_maximum_(), exclusive_minimum_(), multiple_of_()
+        {
+            auto it = sch.find("maximum");
+            if (it != sch.object_range().end()) 
+            {
+                maximum_ = get_number<T>(it->value(), "maximum");
+                absolute_maximum_location_ = make_absolute_keyword_location(uris,"maximum");
+                keywords.insert("maximum");
+            }
+
+            it = sch.find("minimum");
+            if (it != sch.object_range().end()) 
+            {
+                minimum_ = get_number<T>(it->value(), "minimum");
+                absolute_minimum_location_ = make_absolute_keyword_location(uris,"minimum");
+                keywords.insert("minimum");
+            }
+
+            it = sch.find("exclusiveMaximum");
+            if (it != sch.object_range().end()) 
+            {
+                exclusive_maximum_ = get_number<T>(it->value(), "exclusiveMaximum");
+                absolute_exclusive_maximum_location_ = make_absolute_keyword_location(uris,"exclusiveMaximum");
+                keywords.insert("exclusiveMaximum");
+            }
+
+            it = sch.find("exclusiveMinimum");
+            if (it != sch.object_range().end()) 
+            {
+                exclusive_minimum_ = get_number<T>(it->value(), "exclusiveMinimum");
+                absolute_exclusive_minimum_location_ = make_absolute_keyword_location(uris,"exclusiveMinimum");
+                keywords.insert("exclusiveMinimum");
+            }
+
+            it = sch.find("multipleOf");
+            if (it != sch.object_range().end()) 
+            {
+                multiple_of_ = get_number<double>(it->value(), "multipleOf");
+                absolute_multiple_of_location_ = make_absolute_keyword_location(uris,"multipleOf");
+                keywords.insert("multipleOf");
+            }
+        }
+
+    protected:
+
+        void apply_kewords(T value,
+                           const jsonpointer::json_pointer& instance_location, 
+                           const Json& instance, 
+                           error_reporter& reporter) const 
+        {
+            if (multiple_of_ && value != 0) // exclude zero
+            {
+                if (!is_multiple_of(value, *multiple_of_))
+                {
+                    reporter.error(validation_output("multipleOf", 
+                                                     absolute_multiple_of_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " is not a multiple of " + std::to_string(*multiple_of_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (maximum_)
+            {
+                if (value > *maximum_)
+                {
+                    reporter.error(validation_output("maximum", 
+                                                     absolute_maximum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " exceeds maximum of " + std::to_string(*maximum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (minimum_)
+            {
+                if (value < *minimum_)
+                {
+                    reporter.error(validation_output("minimum", 
+                                                     absolute_minimum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " is below minimum of " + std::to_string(*minimum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (exclusive_maximum_)
+            {
+                if (value >= *exclusive_maximum_)
+                {
+                    reporter.error(validation_output("exclusiveMaximum", 
+                                                     absolute_exclusive_maximum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " exceeds maximum of " + std::to_string(*exclusive_maximum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (exclusive_minimum_)
+            {
+                if (value <= *exclusive_minimum_)
+                {
+                    reporter.error(validation_output("exclusiveMinimum", 
+                                                     absolute_exclusive_minimum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " is below minimum of " + std::to_string(*exclusive_minimum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+    private:
+        static bool is_multiple_of(T x, double multiple_of) 
+        {
+            double rem = std::remainder(x, multiple_of);
+            double eps = std::nextafter(x, 0) - x;
+            return std::fabs(rem) < std::fabs(eps);
+        }
+    };
+
+    template <class Json>
+    class integer_validator : public numeric_validator_base<Json,int64_t>
+    {
+    public:
+        integer_validator(const Json& sch, 
+                          const std::vector<schema_location>& uris, 
+                          std::set<std::string>& keywords)
+            : numeric_validator_base<Json, int64_t>(sch, uris, keywords)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const 
+        {
+            if (!(instance.template is_integer<int64_t>() || (instance.is_double() && static_cast<double>(instance.template as<int64_t>()) == instance.template as<double>())))
+            {
+                reporter.error(validation_output("integer", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance is not an integer"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+            int64_t value = instance.template as<int64_t>(); 
+            this->apply_kewords(value, instance_location, instance, reporter);
+        }
+    };
+
+    template <class Json>
+    class number_validator : public numeric_validator_base<Json,double>
+    {
+    public:
+        number_validator(const Json& sch,
+                          const std::vector<schema_location>& uris, 
+                          std::set<std::string>& keywords)
+            : numeric_validator_base<Json, double>(sch, uris, keywords)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const 
+        {
+            if (!(instance.template is_integer<int64_t>() || instance.is_double()))
+            {
+                reporter.error(validation_output("number", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance is not a number"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+            double value = instance.template as<double>(); 
+            this->apply_kewords(value, instance_location, instance, reporter);
+        }
+    };
+
+    // null_validator
+
+    template <class Json>
+    class null_validator : public keyword_validator<Json>
+    {
+    public:
+        null_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const override
+        {
+            if (!instance.is_null())
+            {
+                reporter.error(validation_output("null", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Expected to be null"));
+            }
+        }
+    };
+
+    template <class Json>
+    class boolean_validator : public keyword_validator<Json>
+    {
+    public:
+        boolean_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json&, 
+                         const jsonpointer::json_pointer&, 
+                         error_reporter&, 
+                         Json&) const override
+        {
+        }
+
+    };
+
+    template <class Json>
+    class true_validator : public keyword_validator<Json>
+    {
+    public:
+        true_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json&, 
+                         const jsonpointer::json_pointer&, 
+                         error_reporter&, 
+                         Json&) const override
+        {
+        }
+    };
+
+    template <class Json>
+    class false_validator : public keyword_validator<Json>
+    {
+    public:
+        false_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json&, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const override
+        {
+            reporter.error(validation_output("false", 
+                                             this->absolute_keyword_location(), 
+                                             instance_location.to_uri_fragment(), 
+                                             "False schema always fails"));
+        }
+    };
+
+    template <class Json>
+    class required_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        std::vector<std::string> items_;
+
+    public:
+        required_validator(const std::vector<schema_location>& uris,
+                         const std::vector<std::string>& items)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), items_(items) {}
+        required_validator(const std::string& absolute_keyword_location, const std::vector<std::string>& items)
+            : keyword_validator<Json>(absolute_keyword_location), items_(items) {}
+
+        required_validator(const required_validator&) = delete;
+        required_validator(required_validator&&) = default;
+        required_validator& operator=(const required_validator&) = delete;
+        required_validator& operator=(required_validator&&) = default;
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const override final
+        {
+            for (const auto& key : items_)
+            {
+                if (instance.find(key) == instance.object_range().end())
+                {
+                    reporter.error(validation_output("required", 
+                                                     this->absolute_keyword_location(), 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "Required property \"" + key + "\" not found"));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+    };
+
+    template <class Json>
+    class object_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        jsoncons::optional<std::size_t> max_properties_;
+        std::string absolute_max_properties_location_;
+        jsoncons::optional<std::size_t> min_properties_;
+        std::string absolute_min_properties_location_;
+        jsoncons::optional<required_validator<Json>> required_;
+
+        std::map<std::string, validator_pointer> properties_;
+    #if defined(JSONCONS_HAS_STD_REGEX)
+        std::vector<std::pair<std::regex, validator_pointer>> pattern_properties_;
+    #endif
+        validator_pointer additional_properties_;
+
+        std::map<std::string, validator_pointer> dependencies_;
+
+        validator_pointer property_name_validator_;
+
+    public:
+        object_validator(abstract_keyword_validator_factory<Json>* builder,
+                    const Json& sch,
+                    const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), 
+              max_properties_(), min_properties_(), 
+              additional_properties_(nullptr),
+              property_name_validator_(nullptr)
+        {
+            auto it = sch.find("maxProperties");
+            if (it != sch.object_range().end()) 
+            {
+                max_properties_ = it->value().template as<std::size_t>();
+                absolute_max_properties_location_ = make_absolute_keyword_location(uris, "maxProperties");
+            }
+
+            it = sch.find("minProperties");
+            if (it != sch.object_range().end()) 
+            {
+                min_properties_ = it->value().template as<std::size_t>();
+                absolute_min_properties_location_ = make_absolute_keyword_location(uris, "minProperties");
+            }
+
+            it = sch.find("required");
+            if (it != sch.object_range().end()) 
+            {
+                auto location = make_absolute_keyword_location(uris, "required");
+                required_ = required_validator<Json>(location, 
+                                                   it->value().template as<std::vector<std::string>>());
+            }
+
+            it = sch.find("properties");
+            if (it != sch.object_range().end()) 
+            {
+                for (const auto& prop : it->value().object_range())
+                    properties_.emplace(
+                        std::make_pair(
+                            prop.key(),
+                            builder->make_keyword_validator(prop.value(), uris, {"properties", prop.key()})));
+            }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+            it = sch.find("patternProperties");
+            if (it != sch.object_range().end()) 
+            {
+                for (const auto& prop : it->value().object_range())
+                    pattern_properties_.emplace_back(
+                        std::make_pair(
+                            std::regex(prop.key(), std::regex::ECMAScript),
+                            builder->make_keyword_validator(prop.value(), uris, {prop.key()})));
+            }
+    #endif
+
+            it = sch.find("additionalProperties");
+            if (it != sch.object_range().end()) 
+            {
+                additional_properties_ = builder->make_keyword_validator(it->value(), uris, {"additionalProperties"});
+            }
+
+            it = sch.find("dependencies");
+            if (it != sch.object_range().end()) 
+            {
+                for (const auto& dep : it->value().object_range())
+                {
+                    switch (dep.value().type()) 
+                    {
+                        case json_type::array_value:
+                        {
+                            auto location = make_absolute_keyword_location(uris, "dependencies");
+                            dependencies_.emplace(dep.key(),
+                                                  builder->make_required_validator({location},
+                                                                                 dep.value().template as<std::vector<std::string>>()));
+                            break;
+                        }
+                        default:
+                        {
+                            dependencies_.emplace(dep.key(),
+                                                  builder->make_keyword_validator(dep.value(), uris, {"dependencies", dep.key()}));
+                            break;
+                        }
+                    }
+                }
+            }
+
+            auto property_names_it = sch.find("propertyNames");
+            if (property_names_it != sch.object_range().end()) 
+            {
+                property_name_validator_ = builder->make_keyword_validator(property_names_it->value(), uris, {"propertyNames"});
+            }
+        }
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override
+        {
+            if (max_properties_ && instance.size() > *max_properties_)
+            {
+                std::string message("Maximum properties: " + std::to_string(*max_properties_));
+                message.append(", found: " + std::to_string(instance.size()));
+                reporter.error(validation_output("maxProperties", 
+                                                 absolute_max_properties_location_, 
+                                                 instance_location.to_uri_fragment(), 
+                                                 std::move(message)));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (min_properties_ && instance.size() < *min_properties_)
+            {
+                std::string message("Minimum properties: " + std::to_string(*min_properties_));
+                message.append(", found: " + std::to_string(instance.size()));
+                reporter.error(validation_output("minProperties", 
+                                                 absolute_min_properties_location_, 
+                                                 instance_location.to_uri_fragment(), 
+                                                 std::move(message)));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (required_)
+                required_->validate(instance, instance_location, reporter, patch);
+
+            for (const auto& property : instance.object_range()) 
+            {
+                if (property_name_validator_)
+                    property_name_validator_->validate(property.key(), instance_location, reporter, patch);
+
+                bool a_prop_or_pattern_matched = false;
+                auto properties_it = properties_.find(property.key());
+
+                // check if it is in "properties"
+                if (properties_it != properties_.end()) 
+                {
+                    a_prop_or_pattern_matched = true;
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= property.key();
+                    properties_it->second->validate(property.value(), pointer, reporter, patch);
+                }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+
+                // check all matching "patternProperties"
+                for (auto& schema_pp : pattern_properties_)
+                    if (std::regex_search(property.key(), schema_pp.first)) 
+                    {
+                        a_prop_or_pattern_matched = true;
+                        jsonpointer::json_pointer pointer(instance_location);
+                        pointer /= property.key();
+                        schema_pp.second->validate(property.value(), pointer, reporter, patch);
+                    }
+    #endif
+
+                // finally, check "additionalProperties" 
+                if (!a_prop_or_pattern_matched && additional_properties_) 
+                {
+                    collecting_error_reporter local_reporter;
+
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= property.key();
+                    additional_properties_->validate(property.value(), pointer, local_reporter, patch);
+                    if (!local_reporter.errors.empty())
+                    {
+                        reporter.error(validation_output("additionalProperties", 
+                                                         additional_properties_->absolute_keyword_location(), 
+                                                         instance_location.to_uri_fragment(), 
+                                                         "Additional property \"" + property.key() + "\" found but was invalid."));
+                        if (reporter.fail_early())
+                        {
+                            return;
+                        }
+                    }
+                }
+            }
+
+            // reverse search
+            for (auto const& prop : properties_) 
+            {
+                const auto finding = instance.find(prop.first);
+                if (finding == instance.object_range().end()) 
+                { 
+                    // If property is not in instance
+                    auto default_value = prop.second->get_default_value(instance_location, instance, reporter);
+                    if (default_value) 
+                    { 
+                        // If default value is available, update patch
+                        jsonpointer::json_pointer pointer(instance_location);
+                        pointer /= prop.first;
+
+                        update_patch(patch, pointer, std::move(*default_value));
+                    }
+                }
+            }
+
+            for (const auto& dep : dependencies_) 
+            {
+                auto prop = instance.find(dep.first);
+                if (prop != instance.object_range().end()) 
+                {
+                    // if dependency-property is present in instance
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= dep.first;
+                    dep.second->validate(instance, pointer, reporter, patch); // validate
+                }
+            }
+        }
+
+        void update_patch(Json& patch, const jsonpointer::json_pointer& instance_location, Json&& default_value) const
+        {
+            Json j;
+            j.try_emplace("op", "add"); 
+            j.try_emplace("path", instance_location.to_uri_fragment()); 
+            j.try_emplace("value", std::forward<Json>(default_value)); 
+            patch.push_back(std::move(j));
+        }
+    };
+
+    // array_validator
+
+    template <class Json>
+    class array_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        jsoncons::optional<std::size_t> max_items_;
+        std::string absolute_max_items_location_;
+        jsoncons::optional<std::size_t> min_items_;
+        std::string absolute_min_items_location_;
+        bool unique_items_ = false;
+        validator_pointer items_validator_;
+        std::vector<validator_pointer> item_validators_;
+        validator_pointer additional_items_validator_;
+        validator_pointer contains_validator_;
+
+    public:
+        array_validator(abstract_keyword_validator_factory<Json>* builder, 
+                   const Json& sch, 
+                   const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), 
+              max_items_(), min_items_(), items_validator_(nullptr), additional_items_validator_(nullptr), contains_validator_(nullptr)
+        {
+            {
+                auto it = sch.find("maxItems");
+                if (it != sch.object_range().end()) 
+                {
+                    max_items_ = it->value().template as<std::size_t>();
+                    absolute_max_items_location_ = make_absolute_keyword_location(uris, "maxItems");
+                }
+            }
+
+            {
+                auto it = sch.find("minItems");
+                if (it != sch.object_range().end()) 
+                {
+                    min_items_ = it->value().template as<std::size_t>();
+                    absolute_min_items_location_ = make_absolute_keyword_location(uris, "minItems");
+                }
+            }
+
+            {
+                auto it = sch.find("uniqueItems");
+                if (it != sch.object_range().end()) 
+                {
+                    unique_items_ = it->value().template as<bool>();
+                }
+            }
+
+            {
+                auto it = sch.find("items");
+                if (it != sch.object_range().end()) 
+                {
+
+                    if (it->value().type() == json_type::array_value) 
+                    {
+                        size_t c = 0;
+                        for (const auto& subsch : it->value().array_range())
+                            item_validators_.push_back(builder->make_keyword_validator(subsch, uris, {"items", std::to_string(c++)}));
+
+                        auto attr_add = sch.find("additionalItems");
+                        if (attr_add != sch.object_range().end()) 
+                        {
+                            additional_items_validator_ = builder->make_keyword_validator(attr_add->value(), uris, {"additionalItems"});
+                        }
+
+                    } 
+                    else if (it->value().type() == json_type::object_value ||
+                               it->value().type() == json_type::bool_value)
+                    {
+                        items_validator_ = builder->make_keyword_validator(it->value(), uris, {"items"});
+                    }
+
+                }
+            }
+
+            {
+                auto it = sch.find("contains");
+                if (it != sch.object_range().end()) 
+                {
+                    contains_validator_ = builder->make_keyword_validator(it->value(), uris, {"contains"});
+                }
+            }
+        }
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override
+        {
+            if (max_items_)
+            {
+                if (instance.size() > *max_items_)
+                {
+                    std::string message("Expected maximum item count: " + std::to_string(*max_items_));
+                    message.append(", found: " + std::to_string(instance.size()));
+                    reporter.error(validation_output("maxItems", 
+                                                     absolute_max_items_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::move(message)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (min_items_)
+            {
+                if (instance.size() < *min_items_)
+                {
+                    std::string message("Expected minimum item count: " + std::to_string(*min_items_));
+                    message.append(", found: " + std::to_string(instance.size()));
+                    reporter.error(validation_output("minItems", 
+                                                     absolute_min_items_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::move(message)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (unique_items_) 
+            {
+                if (!array_has_unique_items(instance))
+                {
+                    reporter.error(validation_output("uniqueItems", 
+                                                     this->absolute_keyword_location(), 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "Array items are not unique"));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            size_t index = 0;
+            if (items_validator_)
+            {
+                for (const auto& i : instance.array_range()) 
+                {
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= index;
+                    items_validator_->validate(i, pointer, reporter, patch);
+                    index++;
+                }
+            }
+            else 
+            {
+                auto validator_it = item_validators_.cbegin();
+                for (const auto& item : instance.array_range()) 
+                {
+                    validator_pointer item_validator = nullptr;
+                    if (validator_it != item_validators_.cend())
+                    {
+                        item_validator = *validator_it;
+                        ++validator_it;
+                    }
+                    else if (additional_items_validator_ != nullptr)
+                    {
+                        item_validator = additional_items_validator_;
+                    }
+                    else
+                        break;
+
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= index;
+                    item_validator->validate(item, pointer, reporter, patch);
+                }
+            }
+
+            if (contains_validator_) 
+            {
+                bool contained = false;
+                collecting_error_reporter local_reporter;
+                for (const auto& item : instance.array_range()) 
+                {
+                    std::size_t mark = local_reporter.errors.size();
+                    contains_validator_->validate(item, instance_location, local_reporter, patch);
+                    if (mark == local_reporter.errors.size()) 
+                    {
+                        contained = true;
+                        break;
+                    }
+                }
+                if (!contained)
+                {
+                    reporter.error(validation_output("contains", 
+                                                     this->absolute_keyword_location(), 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "Expected at least one array item to match \"contains\" schema", 
+                                                     local_reporter.errors));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+
+        static bool array_has_unique_items(const Json& a) 
+        {
+            for (auto it = a.array_range().begin(); it != a.array_range().end(); ++it) 
+            {
+                for (auto jt = it+1; jt != a.array_range().end(); ++jt) 
+                {
+                    if (*it == *jt) 
+                    {
+                        return false; // contains duplicates 
+                    }
+                }
+            }
+            return true; // elements are unique
+        }
+    };
+
+    template <class Json>
+    class conditional_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        validator_pointer if_validator_;
+        validator_pointer then_validator_;
+        validator_pointer else_validator_;
+
+    public:
+        conditional_validator(abstract_keyword_validator_factory<Json>* builder,
+                         const Json& sch_if,
+                         const Json& sch,
+                         const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), if_validator_(nullptr), then_validator_(nullptr), else_validator_(nullptr)
+        {
+            auto then_it = sch.find("then");
+            auto else_it = sch.find("else");
+
+            if (then_it != sch.object_range().end() || else_it != sch.object_range().end()) 
+            {
+                if_validator_ = builder->make_keyword_validator(sch_if, uris, {"if"});
+
+                if (then_it != sch.object_range().end()) 
+                {
+                    then_validator_ = builder->make_keyword_validator(then_it->value(), uris, {"then"});
+                }
+
+                if (else_it != sch.object_range().end()) 
+                {
+                    else_validator_ = builder->make_keyword_validator(else_it->value(), uris, {"else"});
+                }
+            }
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const final
+        {
+            if (if_validator_) 
+            {
+                collecting_error_reporter local_reporter;
+
+                if_validator_->validate(instance, instance_location, local_reporter, patch);
+                if (local_reporter.errors.empty()) 
+                {
+                    if (then_validator_)
+                        then_validator_->validate(instance, instance_location, reporter, patch);
+                } 
+                else 
+                {
+                    if (else_validator_)
+                        else_validator_->validate(instance, instance_location, reporter, patch);
+                }
+            }
+        }
+    };
+
+    // enum_validator
+
+    template <class Json>
+    class enum_validator : public keyword_validator<Json>
+    {
+        Json enum_validator_;
+
+    public:
+        enum_validator(const Json& sch,
+                  const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), enum_validator_(sch)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter,
+                         Json&) const final
+        {
+            bool in_range = false;
+            for (const auto& item : enum_validator_.array_range())
+            {
+                if (item == instance) 
+                {
+                    in_range = true;
+                    break;
+                }
+            }
+
+            if (!in_range)
+            {
+                reporter.error(validation_output("enum", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 instance.template as<std::string>() + " is not a valid enum value"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+        }
+    };
+
+    // const_keyword
+
+    template <class Json>
+    class const_keyword : public keyword_validator<Json>
+    {
+        Json const_validator_;
+
+    public:
+        const_keyword(const Json& sch, const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), const_validator_(sch)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter,
+                         Json&) const final
+        {
+            if (const_validator_ != instance)
+                reporter.error(validation_output("const", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance is not const"));
+        }
+    };
+
+    template <class Json>
+    class type_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        Json default_value_;
+        std::vector<validator_pointer> type_mapping_;
+        jsoncons::optional<enum_validator<Json>> enum_validator_;
+        jsoncons::optional<const_keyword<Json>> const_validator_;
+        std::vector<validator_pointer> combined_validators_;
+        jsoncons::optional<conditional_validator<Json>> conditional_validator_;
+        std::vector<std::string> expected_types_;
+
+    public:
+        type_validator(const type_validator&) = delete;
+        type_validator& operator=(const type_validator&) = delete;
+        type_validator(type_validator&&) = default;
+        type_validator& operator=(type_validator&&) = default;
+
+        type_validator(abstract_keyword_validator_factory<Json>* builder,
+                     const Json& sch,
+                     const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), default_value_(jsoncons::null_type()), 
+              type_mapping_((uint8_t)(json_type::object_value)+1), 
+              enum_validator_(), const_validator_()
+        {
+            //std::cout << uris.size() << " uris: ";
+            //for (const auto& uri : uris)
+            //{
+            //    std::cout << uri.string() << ", ";
+            //}
+            //std::cout << "\n";
+            std::set<std::string> known_keywords;
+
+            auto it = sch.find("type");
+            if (it == sch.object_range().end()) 
+            {
+                initialize_type_mapping(builder, "", sch, uris, known_keywords);
+            }
+            else 
+            {
+                switch (it->value().type()) 
+                { 
+                    case json_type::string_value: 
+                    {
+                        auto type = it->value().template as<std::string>();
+                        initialize_type_mapping(builder, type, sch, uris, known_keywords);
+                        expected_types_.emplace_back(std::move(type));
+                        break;
+                    } 
+
+                    case json_type::array_value: // "type": ["type1", "type2"]
+                    {
+                        for (const auto& item : it->value().array_range())
+                        {
+                            auto type = item.template as<std::string>();
+                            initialize_type_mapping(builder, type, sch, uris, known_keywords);
+                            expected_types_.emplace_back(std::move(type));
+                        }
+                        break;
+                    }
+                    default:
+                        break;
+                }
+            }
+
+            const auto default_it = sch.find("default");
+            if (default_it != sch.object_range().end()) 
+            {
+                default_value_ = default_it->value();
+            }
+
+            it = sch.find("enum");
+            if (it != sch.object_range().end()) 
+            {
+                enum_validator_ = enum_validator<Json >(it->value(), uris);
+            }
+
+            it = sch.find("const");
+            if (it != sch.object_range().end()) 
+            {
+                const_validator_ = const_keyword<Json>(it->value(), uris);
+            }
+
+            it = sch.find("not");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_not_validator(it->value(), uris));
+            }
+
+            it = sch.find("allOf");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_all_of_validator(it->value(), uris));
+            }
+
+            it = sch.find("anyOf");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_any_of_validator(it->value(), uris));
+            }
+
+            it = sch.find("oneOf");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_one_of_validator(it->value(), uris));
+            }
+
+            it = sch.find("if");
+            if (it != sch.object_range().end()) 
+            {
+                conditional_validator_ = conditional_validator<Json>(builder, it->value(), sch, uris);
+            }
+        }
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override final
+        {
+            auto type = type_mapping_[(uint8_t) instance.type()];
+
+            if (type)
+                type->validate(instance, instance_location, reporter, patch);
+            else
+            {
+                std::ostringstream ss;
+                ss << "Expected ";
+                for (std::size_t i = 0; i < expected_types_.size(); ++i)
+                {
+                        if (i > 0)
+                        { 
+                            ss << ", ";
+                            if (i+1 == expected_types_.size())
+                            { 
+                                ss << "or ";
+                            }
+                        }
+                        ss << expected_types_[i];
+                }
+                ss << ", found " << instance.type();
+
+                reporter.error(validation_output("type", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 ss.str()));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (enum_validator_)
+            { 
+                enum_validator_->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (const_validator_)
+            { 
+                const_validator_->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            for (const auto& validator : combined_validators_)
+            {
+                validator->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+
+            if (conditional_validator_)
+            { 
+                conditional_validator_->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+        }
+
+        jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer&, 
+                                                   const Json&,
+                                                   error_reporter&) const override
+        {
+            return default_value_;
+        }
+
+        void initialize_type_mapping(abstract_keyword_validator_factory<Json>* builder,
+                                     const std::string& type,
+                                     const Json& sch,
+                                     const std::vector<schema_location>& uris,
+                                     std::set<std::string>& keywords)
+        {
+            if (type == "null")
+            {
+                type_mapping_[(uint8_t)json_type::null_value] = builder->make_null_validator(uris);
+            }
+            else if (type == "object")
+            {
+                type_mapping_[(uint8_t)json_type::object_value] = builder->make_object_validator(sch, uris);
+            }
+            else if (type == "array")
+            {
+                type_mapping_[(uint8_t)json_type::array_value] = builder->make_array_validator(sch, uris);
+            }
+            else if (type == "string")
+            {
+                type_mapping_[(uint8_t)json_type::string_value] = builder->make_string_validator(sch, uris);
+                // For binary types
+                type_mapping_[(uint8_t) json_type::byte_string_value] = type_mapping_[(uint8_t) json_type::string_value];
+            }
+            else if (type == "boolean")
+            {
+                type_mapping_[(uint8_t)json_type::bool_value] = builder->make_boolean_validator(uris);
+            }
+            else if (type == "integer")
+            {
+                type_mapping_[(uint8_t)json_type::int64_value] = builder->make_integer_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::int64_value];
+                type_mapping_[(uint8_t)json_type::double_value] = type_mapping_[(uint8_t)json_type::int64_value];
+            }
+            else if (type == "number")
+            {
+                type_mapping_[(uint8_t)json_type::double_value] = builder->make_number_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::int64_value] = type_mapping_[(uint8_t)json_type::double_value];
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::double_value];
+            }
+            else if (type.empty())
+            {
+                type_mapping_[(uint8_t)json_type::null_value] = builder->make_null_validator(uris);
+                type_mapping_[(uint8_t)json_type::object_value] = builder->make_object_validator(sch, uris);
+                type_mapping_[(uint8_t)json_type::array_value] = builder->make_array_validator(sch, uris);
+                type_mapping_[(uint8_t)json_type::string_value] = builder->make_string_validator(sch, uris);
+                // For binary types
+                type_mapping_[(uint8_t) json_type::byte_string_value] = type_mapping_[(uint8_t) json_type::string_value];
+                type_mapping_[(uint8_t)json_type::bool_value] = builder->make_boolean_validator(uris);
+                type_mapping_[(uint8_t)json_type::int64_value] = builder->make_integer_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::int64_value];
+                type_mapping_[(uint8_t)json_type::double_value] = type_mapping_[(uint8_t)json_type::int64_value];
+                type_mapping_[(uint8_t)json_type::double_value] = builder->make_number_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::int64_value] = type_mapping_[(uint8_t)json_type::double_value];
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::double_value];
+            }
+        }
+    };
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_VALUE_RULES_HPP
diff --git a/include/jsoncons_ext/jsonschema/keyword_validator_factory.hpp b/include/jsoncons_ext/jsonschema/keyword_validator_factory.hpp
new file mode 100644
index 0000000..f538105
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/keyword_validator_factory.hpp
@@ -0,0 +1,556 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_KEYWORD_VALIDATOR_FACTORY_HPP
+#define JSONCONS_JSONSCHEMA_KEYWORD_VALIDATOR_FACTORY_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/subschema.hpp>
+#include <jsoncons_ext/jsonschema/keyword_validator.hpp>
+#include <jsoncons_ext/jsonschema/schema_draft7.hpp>
+#include <jsoncons_ext/jsonschema/schema_version.hpp>
+#include <cassert>
+#include <set>
+#include <sstream>
+#include <iostream>
+#include <cassert>
+#if defined(JSONCONS_HAS_STD_REGEX)
+#include <regex>
+#endif
+
+namespace jsoncons {
+namespace jsonschema {
+
+    template <class Json>
+    using uri_resolver = std::function<Json(const jsoncons::uri & /*id*/)>;
+
+    template <class Json>
+    class reference_schema : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        validator_pointer referred_schema_;
+
+    public:
+        reference_schema(const std::string& id)
+            : keyword_validator<Json>(id), referred_schema_(nullptr) {}
+
+        void set_referred_schema(validator_pointer target) { referred_schema_ = target; }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override
+        {
+            if (!referred_schema_)
+            {
+                reporter.error(validation_output("", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Unresolved schema reference " + this->absolute_keyword_location()));
+                return;
+            }
+
+            referred_schema_->validate(instance, instance_location, reporter, patch);
+        }
+
+        jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer& instance_location, 
+                                                   const Json& instance, 
+                                                   error_reporter& reporter) const override
+        {
+            if (!referred_schema_)
+            {
+                reporter.error(validation_output("", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Unresolved schema reference " + this->absolute_keyword_location()));
+                return jsoncons::optional<Json>();
+            }
+
+            return referred_schema_->get_default_value(instance_location, instance, reporter);
+        }
+    };
+
+    template <class Json>
+    class keyword_validator_factory;
+
+    template <class Json>
+    class json_schema
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        friend class keyword_validator_factory<Json>;
+
+        std::vector<std::unique_ptr<keyword_validator<Json>>> subschemas_;
+        validator_pointer root_;
+    public:
+        json_schema(std::vector<std::unique_ptr<keyword_validator<Json>>>&& subschemas,
+                    validator_pointer root)
+            : subschemas_(std::move(subschemas)), root_(root)
+        {
+            if (root_ == nullptr)
+                JSONCONS_THROW(schema_error("There is no root schema to validate an instance against"));
+        }
+
+        json_schema(const json_schema&) = delete;
+        json_schema(json_schema&&) = default;
+        json_schema& operator=(const json_schema&) = delete;
+        json_schema& operator=(json_schema&&) = default;
+
+        void validate(const Json& instance, 
+                      const jsonpointer::json_pointer& instance_location, 
+                      error_reporter& reporter, 
+                      Json& patch) const 
+        {
+            JSONCONS_ASSERT(root_ != nullptr);
+            root_->validate(instance, instance_location, reporter, patch);
+        }
+    };
+
+    template <class Json>
+    struct default_uri_resolver
+    {
+        Json operator()(const jsoncons::uri& uri)
+        {
+            if (uri.path() == "/draft-07/schema") 
+            {
+                return jsoncons::jsonschema::schema_draft7<Json>::get_schema();
+            }
+
+            JSONCONS_THROW(jsonschema::schema_error("Don't know how to load JSON Schema " + std::string(uri.base())));
+        }
+    };
+
+    template <class Json>
+    class keyword_validator_factory : public abstract_keyword_validator_factory<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        struct subschema_registry
+        {
+            std::map<std::string, validator_pointer> schemas; // schemas
+            std::map<std::string, reference_schema<Json>*> unresolved; // unresolved references
+            std::map<std::string, Json> unprocessed_keywords;
+        };
+
+        uri_resolver<Json> resolver_;
+        validator_pointer root_;
+
+        // Owns all schemas
+        std::vector<std::unique_ptr<keyword_validator<Json>>> subschemas_;
+
+        // Map location to subschema_registry
+        std::map<std::string, subschema_registry> subschema_registries_;
+
+    public:
+        keyword_validator_factory(uri_resolver<Json>&& resolver) noexcept
+
+            : resolver_(std::move(resolver))
+        {
+        }
+
+        keyword_validator_factory(const keyword_validator_factory&) = delete;
+        keyword_validator_factory& operator=(const keyword_validator_factory&) = delete;
+        keyword_validator_factory(keyword_validator_factory&&) = default;
+        keyword_validator_factory& operator=(keyword_validator_factory&&) = default;
+
+        std::shared_ptr<json_schema<Json>> get_schema()
+        {
+            return std::make_shared<json_schema<Json>>(std::move(subschemas_), root_);
+        }
+
+        validator_pointer make_required_validator(const std::vector<schema_location>& uris,
+                                                  const std::vector<std::string>& r) override
+        {
+            auto sch_orig = jsoncons::make_unique<required_validator<Json>>(uris, r);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_null_validator(const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<null_validator<Json>>(uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_true_validator(const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<true_validator<Json>>(uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_false_validator(const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<false_validator<Json>>(uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_object_validator(const Json& schema,
+                                                const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<object_validator<Json>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_array_validator(const Json& schema,
+                                               const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<array_validator<Json>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_string_validator(const Json& schema,
+                                                const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<string_validator<Json>>(schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_boolean_validator(const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<boolean_validator<Json>>(uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_integer_validator(const Json& schema, 
+                                                 const std::vector<schema_location>& uris, 
+                                                 std::set<std::string>& keywords) override
+        {
+            auto sch_orig = jsoncons::make_unique<integer_validator<Json>>(schema, uris, keywords);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_number_validator(const Json& schema, 
+                                                const std::vector<schema_location>& uris, 
+                                                std::set<std::string>& keywords) override
+        {
+            auto sch_orig = jsoncons::make_unique<number_validator<Json>>(schema, uris, keywords);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_not_validator(const Json& schema,
+                                             const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<not_validator<Json>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_all_of_validator(const Json& schema,
+                                                const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<combining_validator<Json,all_of_criterion<Json>>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_any_of_validator(const Json& schema,
+                                                const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<combining_validator<Json,any_of_criterion<Json>>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_one_of_validator(const Json& schema,
+                                                const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<combining_validator<Json,one_of_criterion<Json>>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_type_validator(const Json& schema,
+                                              const std::vector<schema_location>& uris) override
+        {
+            auto sch_orig = jsoncons::make_unique<type_validator<Json>>(this, schema, uris);
+            auto sch = sch_orig.get();
+            subschemas_.emplace_back(std::move(sch_orig));
+            return sch;
+        }
+
+        validator_pointer make_keyword_validator(const Json& schema,
+                                                 const std::vector<schema_location>& uris,
+                                                 const std::vector<std::string>& keys) override
+        {
+            std::vector<schema_location> new_uris = update_uris(schema, uris, keys);
+
+            validator_pointer sch = nullptr;
+
+            switch (schema.type())
+            {
+                case json_type::bool_value:
+                    if (schema.template as<bool>())
+                    {
+                        sch = make_true_validator(new_uris);
+                    }
+                    else
+                    {
+                        sch = make_false_validator(new_uris);
+                    }
+                    break;
+                case json_type::object_value:
+                {
+                    auto it = schema.find("definitions");
+                    if (it != schema.object_range().end()) 
+                    {
+                        for (const auto& def : it->value().object_range())
+                            make_keyword_validator(def.value(), new_uris, {"definitions", def.key()});
+                    }
+
+                    it = schema.find("$ref");
+                    if (it != schema.object_range().end()) // this schema is a reference
+                    { 
+                        schema_location relative(it->value().template as<std::string>()); 
+                        schema_location id = relative.resolve(new_uris.back());
+                        sch = get_or_create_reference(id);
+                    } 
+                    else 
+                    {
+                        sch = make_type_validator(schema, new_uris);
+                    }
+                    break;
+                }
+                default:
+                    JSONCONS_THROW(schema_error("invalid JSON-type for a schema for " + new_uris[0].string() + ", expected: boolean or object"));
+                    break;
+            }
+
+            for (const auto& uri : new_uris) 
+            { 
+                insert(uri, sch);
+
+                if (schema.type() == json_type::object_value)
+                {
+                    for (const auto& item : schema.object_range())
+                        insert_unknown_keyword(uri, item.key(), item.value()); // save unknown keywords for later reference
+                }
+            }
+            return sch;
+        }
+
+        void load_root(const Json& sch)
+        {
+            if (sch.is_object())
+            {
+                auto it = sch.find("$schema");
+                if (it != sch.object_range().end())
+                {
+                    auto sv = it->value().as_string_view();
+                    if (!schema_version::contains(sv))
+                    {
+                        std::string message("Unsupported schema version ");
+                        message.append(sv.data(), sv.size());
+                        JSONCONS_THROW(schema_error(message));
+                    }
+                }
+            }
+            load(sch);
+        }
+
+        void load(const Json& sch)
+        {
+            subschema_registries_.clear();
+            root_ = make_keyword_validator(sch, {{"#"}}, {});
+
+            // load all external schemas that have not already been loaded
+
+            std::size_t loaded_count = 0;
+            do 
+            {
+                loaded_count = 0;
+
+                std::vector<std::string> locations;
+                for (const auto& item : subschema_registries_)
+                    locations.push_back(item.first);
+
+                for (const auto& loc : locations) 
+                {
+                    if (subschema_registries_[loc].schemas.empty()) // registry for this file is empty
+                    { 
+                        if (resolver_) 
+                        {
+                            Json external_schema = resolver_(loc);
+                            make_keyword_validator(external_schema, {{loc}}, {});
+                            ++loaded_count;
+                        } 
+                        else 
+                        {
+                            JSONCONS_THROW(schema_error("External schema reference '" + loc + "' needs to be loaded, but no resolver provided"));
+                        }
+                    }
+                }
+            } 
+            while (loaded_count > 0);
+
+            for (const auto &file : subschema_registries_)
+            {
+                if (!file.second.unresolved.empty())
+                {
+                    JSONCONS_THROW(schema_error("after all files have been parsed, '" +
+                                                (file.first == "" ? "<root>" : file.first) +
+                                                "' has still undefined references."));
+                }
+            }
+        }
+
+    private:
+
+        void insert(const schema_location& uri, validator_pointer s)
+        {
+            auto& file = get_or_create_file(std::string(uri.base()));
+            auto schemas_it = file.schemas.find(std::string(uri.fragment()));
+            if (schemas_it != file.schemas.end()) 
+            {
+                JSONCONS_THROW(schema_error("schema with " + uri.string() + " already inserted"));
+                return;
+            }
+
+            file.schemas.insert({std::string(uri.fragment()), s});
+
+            // is there an unresolved reference to this newly inserted schema?
+            auto unresolved_it = file.unresolved.find(std::string(uri.fragment()));
+            if (unresolved_it != file.unresolved.end()) 
+            {
+                unresolved_it->second->set_referred_schema(s);
+                file.unresolved.erase(unresolved_it);
+
+            }
+        }
+
+        void insert_unknown_keyword(const schema_location& uri, 
+                                    const std::string& key, 
+                                    const Json& value)
+        {
+            auto &file = get_or_create_file(std::string(uri.base()));
+            auto new_u = uri.append(key);
+            schema_location new_uri(new_u);
+
+            if (new_uri.has_fragment() && !new_uri.has_identifier()) 
+            {
+                auto fragment = std::string(new_uri.fragment());
+                // is there a reference looking for this unknown-keyword, which is thus no longer a unknown keyword but a schema
+                auto unresolved = file.unresolved.find(fragment);
+                if (unresolved != file.unresolved.end())
+                    make_keyword_validator(value, {{new_uri}}, {});
+                else // no, nothing ref'd it, keep for later
+                    file.unprocessed_keywords[fragment] = value;
+
+                // recursively add possible subschemas of unknown keywords
+                if (value.type() == json_type::object_value)
+                    for (const auto& subsch : value.object_range())
+                    {
+                        insert_unknown_keyword(new_uri, subsch.key(), subsch.value());
+                    }
+            }
+        }
+
+        validator_pointer get_or_create_reference(const schema_location& uri)
+        {
+            auto &file = get_or_create_file(std::string(uri.base()));
+
+            // a schema already exists
+            auto sch = file.schemas.find(std::string(uri.fragment()));
+            if (sch != file.schemas.end())
+                return sch->second;
+
+            // referencing an unknown keyword, turn it into schema
+            //
+            // an unknown keyword can only be referenced by a JSONPointer,
+            // not by a plain name identifier
+            if (uri.has_fragment() && !uri.has_identifier()) 
+            {
+                std::string fragment = std::string(uri.fragment());
+                auto unprocessed_keywords_it = file.unprocessed_keywords.find(fragment);
+                if (unprocessed_keywords_it != file.unprocessed_keywords.end()) 
+                {
+                    auto &subsch = unprocessed_keywords_it->second; 
+                    auto s = make_keyword_validator(subsch, {{uri}}, {});       //  A JSON Schema MUST be an object or a boolean.
+                    file.unprocessed_keywords.erase(unprocessed_keywords_it);
+                    return s;
+                }
+            }
+
+            // get or create a reference_schema
+            auto ref = file.unresolved.find(std::string(uri.fragment()));
+            if (ref != file.unresolved.end()) 
+            {
+                return ref->second; // unresolved, use existing reference
+            } 
+            else 
+            {
+                auto orig = jsoncons::make_unique<reference_schema<Json>>(uri.string());
+                auto p = file.unresolved.insert(ref,
+                                              {std::string(uri.fragment()), orig.get()})
+                    ->second; // unresolved, create new reference
+                
+                subschemas_.emplace_back(std::move(orig));
+                return p;
+            }
+        }
+
+        subschema_registry& get_or_create_file(const std::string& loc)
+        {
+            auto file = subschema_registries_.find(loc);
+            if (file != subschema_registries_.end())
+                return file->second;
+            else
+                return subschema_registries_.insert(file, {loc, {}})->second;
+        }
+
+    };
+
+    template <class Json>
+    std::shared_ptr<json_schema<Json>> make_schema(const Json& schema)
+    {
+        keyword_validator_factory<Json> loader{default_uri_resolver<Json>()};
+        loader.load_root(schema);
+
+        return loader.get_schema();
+    }
+
+    template <class Json,class URIResolver>
+    typename std::enable_if<type_traits::is_unary_function_object_exact<URIResolver,Json,std::string>::value,std::shared_ptr<json_schema<Json>>>::type
+    make_schema(const Json& schema, const URIResolver& resolver)
+    {
+        keyword_validator_factory<Json> loader(resolver);
+        loader.load_root(schema);
+
+        return loader.get_schema();
+    }
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_SCHEMA_LOADER_HPP
diff --git a/include/jsoncons_ext/jsonschema/schema_draft7.hpp b/include/jsoncons_ext/jsonschema/schema_draft7.hpp
new file mode 100644
index 0000000..c6f6fbc
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/schema_draft7.hpp
@@ -0,0 +1,198 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_SCHEMA_DRAFT7_HPP
+#define JSONCONS_JSONSCHEMA_SCHEMA_DRAFT7_HPP
+
+#include <jsoncons/json.hpp>
+
+namespace jsoncons {
+namespace jsonschema {
+    
+    template <class Json>
+    struct schema_draft7
+    {
+        static Json get_schema() 
+        {
+            static Json schema = Json::parse(R"(
+    {
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        "$id": "http://json-schema.org/draft-07/schema#",
+        "title": "Core schema meta-schema",
+        "definitions": {
+            "schemaArray": {
+                "type": "array",
+                "minItems": 1,
+                "items": { "$ref": "#" }
+            },
+            "nonNegativeInteger": {
+                "type": "integer",
+                "minimum": 0
+            },
+            "nonNegativeIntegerDefault0": {
+                "allOf": [
+                    { "$ref": "#/definitions/nonNegativeInteger" },
+                    { "default": 0 }
+                ]
+            },
+            "simpleTypes": {
+                "enum": [
+                    "array",
+                    "boolean",
+                    "integer",
+                    "null",
+                    "number",
+                    "object",
+                    "string"
+                ]
+            },
+            "stringArray": {
+                "type": "array",
+                "items": { "type": "string" },
+                "uniqueItems": true,
+                "default": []
+            }
+        },
+        "type": ["object", "boolean"],
+        "properties": {
+            "$id": {
+                "type": "string",
+                "format": "uri-reference"
+            },
+            "$schema": {
+                "type": "string",
+                "format": "uri"
+            },
+            "$ref": {
+                "type": "string",
+                "format": "uri-reference"
+            },
+            "$comment": {
+                "type": "string"
+            },
+            "title": {
+                "type": "string"
+            },
+            "description": {
+                "type": "string"
+            },
+            "default": true,
+            "readOnly": {
+                "type": "boolean",
+                "default": false
+            },
+            "examples": {
+                "type": "array",
+                "items": true
+            },
+            "multipleOf": {
+                "type": "number",
+                "exclusiveMinimum": 0
+            },
+            "maximum": {
+                "type": "number"
+            },
+            "exclusiveMaximum": {
+                "type": "number"
+            },
+            "minimum": {
+                "type": "number"
+            },
+            "exclusiveMinimum": {
+                "type": "number"
+            },
+            "maxLength": { "$ref": "#/definitions/nonNegativeInteger" },
+            "minLength": { "$ref": "#/definitions/nonNegativeIntegerDefault0" },
+            "pattern": {
+                "type": "string",
+                "format": "regex"
+            },
+            "additionalItems": { "$ref": "#" },
+            "items": {
+                "anyOf": [
+                    { "$ref": "#" },
+                    { "$ref": "#/definitions/schemaArray" }
+                ],
+                "default": true
+            },
+            "maxItems": { "$ref": "#/definitions/nonNegativeInteger" },
+            "minItems": { "$ref": "#/definitions/nonNegativeIntegerDefault0" },
+            "uniqueItems": {
+                "type": "boolean",
+                "default": false
+            },
+            "contains": { "$ref": "#" },
+            "maxProperties": { "$ref": "#/definitions/nonNegativeInteger" },
+            "minProperties": { "$ref": "#/definitions/nonNegativeIntegerDefault0" },
+            "required": { "$ref": "#/definitions/stringArray" },
+            "additionalProperties": { "$ref": "#" },
+            "definitions": {
+                "type": "object",
+                "additionalProperties": { "$ref": "#" },
+                "default": {}
+            },
+            "properties": {
+                "type": "object",
+                "additionalProperties": { "$ref": "#" },
+                "default": {}
+            },
+            "patternProperties": {
+                "type": "object",
+                "additionalProperties": { "$ref": "#" },
+                "propertyNames": { "format": "regex" },
+                "default": {}
+            },
+            "dependencies": {
+                "type": "object",
+                "additionalProperties": {
+                    "anyOf": [
+                        { "$ref": "#" },
+                        { "$ref": "#/definitions/stringArray" }
+                    ]
+                }
+            },
+            "propertyNames": { "$ref": "#" },
+            "const": true,
+            "enum": {
+                "type": "array",
+                "items": true,
+                "minItems": 1,
+                "uniqueItems": true
+            },
+            "type": {
+                "anyOf": [
+                    { "$ref": "#/definitions/simpleTypes" },
+                    {
+                        "type": "array",
+                        "items": { "$ref": "#/definitions/simpleTypes" },
+                        "minItems": 1,
+                        "uniqueItems": true
+                    }
+                ]
+            },
+            "format": { "type": "string" },
+            "contentMediaType": { "type": "string" },
+            "contentEncoding": { "type": "string" },
+            "if": { "$ref": "#" },
+            "then": { "$ref": "#" },
+            "else": { "$ref": "#" },
+            "allOf": { "$ref": "#/definitions/schemaArray" },
+            "anyOf": { "$ref": "#/definitions/schemaArray" },
+            "oneOf": { "$ref": "#/definitions/schemaArray" },
+            "not": { "$ref": "#" }
+        },
+        "default": true
+    } 
+            )"); 
+
+            return schema;
+        }
+    };
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_SCHEMA_DRAFT7_HPP
diff --git a/include/jsoncons_ext/jsonschema/schema_location.hpp b/include/jsoncons_ext/jsonschema/schema_location.hpp
new file mode 100644
index 0000000..fd1a743
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/schema_location.hpp
@@ -0,0 +1,200 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_SCHEMA_LOCATION_HPP
+#define JSONCONS_JSONSCHEMA_SCHEMA_LOCATION_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/jsonschema_error.hpp>
+
+namespace jsoncons {
+namespace jsonschema {
+
+    class schema_location
+    {
+        jsoncons::uri uri_;
+        std::string identifier_;
+    public:
+        schema_location()
+        {
+        }
+
+        schema_location(const std::string& uri)
+        {
+            auto pos = uri.find('#');
+            if (pos != std::string::npos)
+            {
+                identifier_ = uri.substr(pos + 1); 
+                unescape_percent(identifier_);
+            }
+            uri_ = jsoncons::uri(uri);
+        }
+
+        jsoncons::uri uri() const
+        {
+            return uri_;
+        }
+
+        bool has_fragment() const
+        {
+            return !identifier_.empty();
+        }
+
+        bool has_identifier() const
+        {
+            return !identifier_.empty() && identifier_.front() != '/';
+        }
+
+        jsoncons::string_view base() const
+        {
+            return uri_.base();
+        }
+
+        jsoncons::string_view path() const
+        {
+            return uri_.path();
+        }
+
+        bool is_absolute() const
+        {
+            return uri_.is_absolute();
+        }
+
+        std::string identifier() const
+        {
+            return identifier_;
+        }
+
+        std::string fragment() const
+        {
+            return identifier_;
+        }
+
+        schema_location resolve(const schema_location& uri) const
+        {
+            schema_location new_uri;
+            new_uri.identifier_ = identifier_;
+            new_uri.uri_ = uri_.resolve(uri.uri_);
+            return new_uri;
+        }
+
+        int compare(const schema_location& other) const
+        {
+            int result = uri_.compare(other.uri_);
+            if (result != 0) 
+            {
+                return result;
+            }
+            return result; 
+        }
+
+        schema_location append(const std::string& field) const
+        {
+            if (has_identifier())
+                return *this;
+
+            jsoncons::jsonpointer::json_pointer pointer(std::string(uri_.fragment()));
+            pointer /= field;
+
+            jsoncons::uri new_uri(uri_.scheme(),
+                                  uri_.userinfo(),
+                                  uri_.host(),
+                                  uri_.port(),
+                                  uri_.path(),
+                                  uri_.query(),
+                                  pointer.to_string());
+
+            schema_location wrapper;
+            wrapper.uri_ = new_uri;
+            wrapper.identifier_ = pointer.to_string();
+
+            return wrapper;
+        }
+
+        schema_location append(std::size_t index) const
+        {
+            if (has_identifier())
+                return *this;
+
+            jsoncons::jsonpointer::json_pointer pointer(std::string(uri_.fragment()));
+            pointer /= index;
+
+            jsoncons::uri new_uri(uri_.scheme(),
+                                  uri_.userinfo(),
+                                  uri_.host(),
+                                  uri_.port(),
+                                  uri_.path(),
+                                  uri_.query(),
+                                  pointer.to_string());
+
+            schema_location wrapper;
+            wrapper.uri_ = new_uri;
+            wrapper.identifier_ = pointer.to_string();
+
+            return wrapper;
+        }
+
+        std::string string() const
+        {
+            std::string s = uri_.string();
+            return s;
+        }
+
+        friend bool operator==(const schema_location& lhs, const schema_location& rhs)
+        {
+            return lhs.compare(rhs) == 0;
+        }
+
+        friend bool operator!=(const schema_location& lhs, const schema_location& rhs)
+        {
+            return lhs.compare(rhs) != 0;
+        }
+
+        friend bool operator<(const schema_location& lhs, const schema_location& rhs)
+        {
+            return lhs.compare(rhs) < 0;
+        }
+
+        friend bool operator<=(const schema_location& lhs, const schema_location& rhs)
+        {
+            return lhs.compare(rhs) <= 0;
+        }
+
+        friend bool operator>(const schema_location& lhs, const schema_location& rhs)
+        {
+            return lhs.compare(rhs) > 0;
+        }
+
+        friend bool operator>=(const schema_location& lhs, const schema_location& rhs)
+        {
+            return lhs.compare(rhs) >= 0;
+        }
+    private:
+        static void unescape_percent(std::string& s)
+        {
+            if (s.size() >= 3)
+            {
+                std::size_t pos = s.size() - 2;
+                while (pos-- >= 1)
+                {
+                    if (s[pos] == '%')
+                    {
+                        std::string hex = s.substr(pos + 1, 2);
+                        char ch = (char) std::strtoul(hex.c_str(), nullptr, 16);
+                        s.replace(pos, 3, 1, ch);
+                    }
+                }
+            }
+        }
+    };
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_RULE_HPP
diff --git a/include/jsoncons_ext/jsonschema/schema_version.hpp b/include/jsoncons_ext/jsonschema/schema_version.hpp
new file mode 100644
index 0000000..b804712
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/schema_version.hpp
@@ -0,0 +1,35 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_SCHEMA_VERSION_HPP
+#define JSONCONS_JSONSCHEMA_SCHEMA_VERSION_HPP
+
+#include <jsoncons/json.hpp>
+
+namespace jsoncons {
+namespace jsonschema {
+
+    class schema_version
+    {
+    public:
+        static bool contains(const string_view& url)
+        {
+            if (url.find("json-schema.org/draft-07/schema#") != string_view::npos)
+            {
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+    };
+
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_JSONSCHEMA_VERSION_HPP
diff --git a/include/jsoncons_ext/jsonschema/subschema.hpp b/include/jsoncons_ext/jsonschema/subschema.hpp
new file mode 100644
index 0000000..cbe0af4
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/subschema.hpp
@@ -0,0 +1,144 @@
+// Copyright 2020 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONSCHEMA_SUBSCHEMA_HPP
+#define JSONCONS_JSONSCHEMA_SUBSCHEMA_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/jsonschema_error.hpp>
+#include <jsoncons_ext/jsonschema/schema_location.hpp>
+
+namespace jsoncons {
+namespace jsonschema {
+
+    // Interface for validation error handlers
+    class error_reporter
+    {
+        bool fail_early_;
+        std::size_t error_count_;
+    public:
+        error_reporter(bool fail_early = false)
+            : fail_early_(fail_early), error_count_(0)
+        {
+        }
+
+        virtual ~error_reporter() = default;
+
+        void error(const validation_output& o)
+        {
+            ++error_count_;
+            do_error(o);
+        }
+
+        std::size_t error_count() const
+        {
+            return error_count_;
+        }
+
+        bool fail_early() const
+        {
+            return fail_early_;
+        }
+
+    private:
+        virtual void do_error(const validation_output& /* e */) = 0;
+    };
+
+    template <class Json>
+    class keyword_validator 
+    {
+        std::string absolute_keyword_location_;
+    public:
+        using self_pointer = keyword_validator<Json>*;
+
+        keyword_validator(const std::string& absolute_keyword_location)
+            : absolute_keyword_location_(absolute_keyword_location)
+        {
+        }
+
+        keyword_validator(const keyword_validator&) = delete;
+        keyword_validator(keyword_validator&&) = default;
+        keyword_validator& operator=(const keyword_validator&) = delete;
+        keyword_validator& operator=(keyword_validator&&) = default;
+
+        virtual ~keyword_validator() = default;
+
+        const std::string& absolute_keyword_location() const
+        {
+            return absolute_keyword_location_;
+        }
+
+        void validate(const Json& instance, 
+                      const jsonpointer::json_pointer& instance_location, 
+                      error_reporter& reporter, 
+                      Json& patch) const 
+        {
+            do_validate(instance, 
+                        instance_location,
+                        reporter,
+                        patch);
+        }
+
+        virtual jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer&, const Json&, error_reporter&) const
+        {
+            return jsoncons::optional<Json>();
+        }
+
+    private:
+        virtual void do_validate(const Json& instance, 
+                                 const jsonpointer::json_pointer& instance_location, 
+                                 error_reporter& reporter, 
+                                 Json& patch) const = 0;
+    };
+
+    template <class Json>
+    std::vector<schema_location> update_uris(const Json& schema,
+                                         const std::vector<schema_location>& uris,
+                                         const std::vector<std::string>& keys)
+    {
+        // Exclude uri's that are not plain name identifiers
+        std::vector<schema_location> new_uris;
+        for (const auto& uri : uris)
+        {
+            if (!uri.has_identifier())
+                new_uris.push_back(uri);
+        }
+
+        // Append the keys for this sub-schema to the uri's
+        for (const auto& key : keys)
+        {
+            for (auto& uri : new_uris)
+            {
+                auto new_u = uri.append(key);
+                uri = schema_location(new_u);
+            }
+        }
+        if (schema.type() == json_type::object_value)
+        {
+            auto it = schema.find("$id"); // If $id is found, this schema can be referenced by the id
+            if (it != schema.object_range().end()) 
+            {
+                std::string id = it->value().template as<std::string>(); 
+                // Add it to the list if it is not already there
+                if (std::find(new_uris.begin(), new_uris.end(), id) == new_uris.end())
+                {
+                    schema_location relative(id); 
+                    schema_location new_uri = relative.resolve(new_uris.back());
+                    new_uris.emplace_back(new_uri); 
+                }
+            }
+        }
+
+        return new_uris;
+    }
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_RULE_HPP
diff --git a/include/jsoncons_ext/mergepatch/mergepatch.hpp b/include/jsoncons_ext/mergepatch/mergepatch.hpp
new file mode 100644
index 0000000..c5fdefe
--- /dev/null
+++ b/include/jsoncons_ext/mergepatch/mergepatch.hpp
@@ -0,0 +1,103 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONMERGEPATCH_JSONMERGEPATCH_HPP
+#define JSONCONS_JSONMERGEPATCH_JSONMERGEPATCH_HPP
+
+#include <string>
+#include <vector> 
+#include <memory>
+#include <algorithm> // std::min
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+
+namespace jsoncons { 
+namespace mergepatch {
+
+    template <class Json>
+    Json from_diff(const Json& source, const Json& target)
+    {
+        if (!source.is_object() || !target.is_object())
+        {
+            return target;
+        }
+        Json result(json_object_arg);
+
+        for (const auto& member : source.object_range())
+        {
+            auto it = target.find(member.key());
+            if (it != target.object_range().end())
+            {
+                if (member.value() != it->value())
+                {
+                    result.try_emplace(member.key(), from_diff(member.value(), it->value()));
+                }
+            }
+            else
+            {
+                result.try_emplace(member.key(), Json::null());
+            }
+        }
+
+        for (const auto& member : target.object_range())
+        {
+            auto it = source.find(member.key());
+            if (it == source.object_range().end())
+            {
+                result.try_emplace(member.key(), member.value());
+            }
+        }
+
+        return result;
+    }
+
+    namespace detail {
+        template <class Json>
+        Json apply_merge_patch_(Json& target, const Json& patch)
+        {
+            if (patch.is_object())
+            {
+                if (!target.is_object())
+                {
+                    target = Json(json_object_arg);
+                }
+                for (auto& member : patch.object_range())
+                {
+                    auto it = target.find(member.key());
+                    if (it != target.object_range().end())
+                    {
+                        Json item = it->value();
+                        target.erase(it);
+                        if (!member.value().is_null())
+                        {
+                            target.try_emplace(member.key(), apply_merge_patch_(item, member.value()));
+                        }
+                    }
+                    else if (!member.value().is_null())
+                    {
+                        Json item(json_object_arg);
+                        target.try_emplace(member.key(), apply_merge_patch_(item, member.value()));
+                    }
+                }
+                return target;
+            }
+            else
+            {
+                return patch;
+            }
+        }
+    } // namespace detail
+
+    template <class Json>
+    void apply_merge_patch(Json& target, const Json& patch)
+    {
+        target = detail::apply_merge_patch_(target, patch);
+    }
+
+} // namespace mergepatch
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/decode_msgpack.hpp b/include/jsoncons_ext/msgpack/decode_msgpack.hpp
new file mode 100644
index 0000000..614af3d
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/decode_msgpack.hpp
@@ -0,0 +1,202 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_DECODE_MSGPACK_HPP
+#define JSONCONS_MSGPACK_DECODE_MSGPACK_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/msgpack/msgpack_encoder.hpp>
+#include <jsoncons_ext/msgpack/msgpack_reader.hpp>
+#include <jsoncons_ext/msgpack/msgpack_cursor.hpp>
+
+namespace jsoncons { 
+namespace msgpack {
+
+    template<class T, class Source>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_msgpack(const Source& v, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_msgpack_reader<jsoncons::bytes_source> reader(v, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_msgpack(const Source& v, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        basic_msgpack_cursor<bytes_source> cursor(v, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_msgpack(std::istream& is, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        msgpack_stream_reader reader(is, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_msgpack(std::istream& is, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        basic_msgpack_cursor<binary_stream_source> cursor(is, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_msgpack(InputIt first, InputIt last,
+                const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_msgpack_reader<binary_iterator_source<InputIt>> reader(binary_iterator_source<InputIt>(first, last), adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_msgpack(InputIt first, InputIt last,
+                const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        basic_msgpack_cursor<binary_iterator_source<InputIt>> cursor(binary_iterator_source<InputIt>(first, last), options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    // With leading allocator parameter
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                   const Source& v, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_msgpack_reader<jsoncons::bytes_source,TempAllocator> reader(v, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                   const Source& v, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        basic_msgpack_cursor<bytes_source,TempAllocator> cursor(v, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                   std::istream& is, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_msgpack_reader<jsoncons::binary_stream_source,TempAllocator> reader(is, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                   std::istream& is, 
+                   const msgpack_decode_options& options = msgpack_decode_options())
+    {
+        basic_msgpack_cursor<binary_stream_source,TempAllocator> cursor(is, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+} // msgpack
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/encode_msgpack.hpp b/include/jsoncons_ext/msgpack/encode_msgpack.hpp
new file mode 100644
index 0000000..10a61e0
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/encode_msgpack.hpp
@@ -0,0 +1,142 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_ENCODE_MSGPACK_HPP
+#define JSONCONS_MSGPACK_ENCODE_MSGPACK_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/msgpack/msgpack_encoder.hpp>
+#include <jsoncons_ext/msgpack/msgpack_reader.hpp>
+
+namespace jsoncons { 
+namespace msgpack {
+
+    template<class T, class Container>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_msgpack(const T& j, 
+                   Container& v, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_msgpack_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_msgpack(const T& val, 
+                   Container& v, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        basic_msgpack_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_msgpack(const T& j, 
+                   std::ostream& os, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        using char_type = typename T::char_type;
+        msgpack_stream_encoder encoder(os, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_msgpack(const T& val, 
+                   std::ostream& os, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        msgpack_stream_encoder encoder(os, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    // with temp_allocator_arg_t
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc, const T& j, 
+                   Container& v, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_msgpack_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc, 
+                   const T& val, Container& v, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        basic_msgpack_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc, 
+                   const T& j, 
+                   std::ostream& os, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_msgpack_encoder<jsoncons::binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_msgpack(temp_allocator_arg_t, const TempAllocator& temp_alloc, 
+                   const T& val, 
+                   std::ostream& os, 
+                   const msgpack_encode_options& options = msgpack_encode_options())
+    {
+        basic_msgpack_encoder<jsoncons::binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+} // msgpack
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/msgpack.hpp b/include/jsoncons_ext/msgpack/msgpack.hpp
new file mode 100644
index 0000000..307aad2
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack.hpp
@@ -0,0 +1,24 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_HPP
+#define JSONCONS_MSGPACK_MSGPACK_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/msgpack/msgpack_encoder.hpp>
+#include <jsoncons_ext/msgpack/msgpack_reader.hpp>
+#include <jsoncons_ext/msgpack/msgpack_cursor.hpp>
+#include <jsoncons_ext/msgpack/encode_msgpack.hpp>
+#include <jsoncons_ext/msgpack/decode_msgpack.hpp>
+
+#endif
+
diff --git a/include/jsoncons_ext/msgpack/msgpack_cursor.hpp b/include/jsoncons_ext/msgpack/msgpack_cursor.hpp
new file mode 100644
index 0000000..a813429
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_cursor.hpp
@@ -0,0 +1,343 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_CURSOR_HPP
+#define JSONCONS_MSGPACK_MSGPACK_CURSOR_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/staj_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons_ext/msgpack/msgpack_parser.hpp>
+
+namespace jsoncons { 
+namespace msgpack {
+
+template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>>
+class basic_msgpack_cursor : public basic_staj_cursor<char>, private virtual ser_context
+{
+public:
+    using source_type = Source;
+    using char_type = char;
+    using allocator_type = Allocator;
+private:
+    basic_msgpack_parser<Source,Allocator> parser_;
+    basic_staj_visitor<char_type> cursor_visitor_;
+    basic_json_visitor2_to_visitor_adaptor<char_type,Allocator> cursor_handler_adaptor_;
+    bool eof_;
+
+    // Noncopyable and nonmoveable
+    basic_msgpack_cursor(const basic_msgpack_cursor&) = delete;
+    basic_msgpack_cursor& operator=(const basic_msgpack_cursor&) = delete;
+
+public:
+    using string_view_type = string_view;
+
+    template <class Sourceable>
+    basic_msgpack_cursor(Sourceable&& source,
+                         const msgpack_decode_options& options = msgpack_decode_options(),
+                         const Allocator& alloc = Allocator())
+        : parser_(std::forward<Sourceable>(source), options, alloc), 
+          cursor_visitor_(accept_all),
+          cursor_handler_adaptor_(cursor_visitor_, alloc),
+          eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    // Constructors that set parse error codes
+
+    template <class Sourceable>
+    basic_msgpack_cursor(Sourceable&& source,
+                         std::error_code& ec)
+       : basic_msgpack_cursor(std::allocator_arg, Allocator(),
+                              std::forward<Sourceable>(source), 
+                              msgpack_decode_options(), 
+                              ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_msgpack_cursor(Sourceable&& source,
+                         const msgpack_decode_options& options,
+                         std::error_code& ec)
+       : basic_msgpack_cursor(std::allocator_arg, Allocator(),
+                              std::forward<Sourceable>(source), 
+                              options, 
+                              ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_msgpack_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                         Sourceable&& source,
+                         const msgpack_decode_options& options,
+                         std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(accept_all),
+         cursor_handler_adaptor_(cursor_visitor_, alloc),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    void reset()
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    void reset(std::error_code& ec)
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source, std::error_code& ec)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        cursor_handler_adaptor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    bool done() const override
+    {
+        return parser_.done();
+    }
+
+    const staj_event& current() const override
+    {
+        return cursor_visitor_.event();
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor) override
+    {
+        std::error_code ec;
+        read_to(visitor, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor,
+                std::error_code& ec) override
+    {
+        if (cursor_visitor_.dump(visitor, *this, ec))
+        {
+            read_next(visitor, ec);
+        }
+    }
+
+    void next() override
+    {
+        std::error_code ec;
+        next(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void next(std::error_code& ec) override
+    {
+        read_next(ec);
+    }
+
+    const ser_context& context() const override
+    {
+        return *this;
+    }
+
+    bool eof() const
+    {
+        return eof_;
+    }
+
+    std::size_t line() const override
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const override
+    {
+        return parser_.column();
+    }
+
+    friend
+    staj_filter_view operator|(basic_msgpack_cursor& cursor, 
+                               std::function<bool(const staj_event&, const ser_context&)> pred)
+    {
+        return staj_filter_view(cursor, pred);
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_msgpack_cursor(Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      const msgpack_decode_options& options = msgpack_decode_options(),
+                      const Allocator& alloc = Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(filter), 
+         cursor_handler_adaptor_(cursor_visitor_, alloc),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_msgpack_cursor(Sourceable&& source,
+                         std::function<bool(const staj_event&, const ser_context&)> filter,
+                         std::error_code& ec)
+       : basic_msgpack_cursor(std::allocator_arg, Allocator(),
+                              std::forward<Sourceable>(source), filter, ec)
+    {
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_msgpack_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                         Sourceable&& source,
+                         std::function<bool(const staj_event&, const ser_context&)> filter,
+                         std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), alloc), 
+         cursor_visitor_(filter),
+         cursor_handler_adaptor_(cursor_visitor_, alloc),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&)")
+    void read(basic_json_visitor<char_type>& visitor)
+    {
+        read_to(visitor);
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&, std::error_code&)")
+    void read(basic_json_visitor<char_type>& visitor,
+                 std::error_code& ec) 
+    {
+        read_to(visitor, ec);
+    }
+#endif
+private:
+    static bool accept_all(const staj_event&, const ser_context&) 
+    {
+        return true;
+    }
+
+    void read_next(std::error_code& ec)
+    {
+        if (cursor_visitor_.in_available())
+        {
+            cursor_visitor_.send_available(ec);
+        }
+        else
+        {
+            parser_.restart();
+            while (!parser_.stopped())
+            {
+                parser_.parse(cursor_handler_adaptor_, ec);
+                if (ec) return;
+            }
+        }
+    }
+
+    void read_next(basic_json_visitor<char_type>& visitor, std::error_code& ec)
+    {
+        {
+            struct resource_wrapper
+            {
+                basic_json_visitor2_to_visitor_adaptor<char_type,Allocator>& adaptor;
+                basic_json_visitor<char_type>& original;
+
+                resource_wrapper(basic_json_visitor2_to_visitor_adaptor<char_type,Allocator>& adaptor,
+                                 basic_json_visitor<char_type>& visitor)
+                    : adaptor(adaptor), original(adaptor.destination())
+                {
+                    adaptor.destination(visitor);
+                }
+
+                ~resource_wrapper()
+                {
+                    adaptor.destination(original);
+                }
+            } wrapper(cursor_handler_adaptor_, visitor);
+
+            parser_.restart();
+            while (!parser_.stopped())
+            {
+                parser_.parse(cursor_handler_adaptor_, ec);
+                if (ec) return;
+            }
+        }
+    }
+};
+
+using msgpack_stream_cursor = basic_msgpack_cursor<jsoncons::binary_stream_source>;
+using msgpack_bytes_cursor = basic_msgpack_cursor<jsoncons::bytes_source>;
+
+} // namespace msgpack
+} // namespace jsoncons
+
+#endif
+
diff --git a/include/jsoncons_ext/msgpack/msgpack_cursor2.hpp b/include/jsoncons_ext/msgpack/msgpack_cursor2.hpp
new file mode 100644
index 0000000..8fce1ca
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_cursor2.hpp
@@ -0,0 +1,259 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_CURSOR2_HPP
+#define JSONCONS_MSGPACK_MSGPACK_CURSOR2_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor2.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/staj2_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons_ext/msgpack/msgpack_parser.hpp>
+
+namespace jsoncons { 
+namespace msgpack {
+
+    template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>>
+    class basic_msgpack_cursor2 : public basic_staj2_cursor<char>, private virtual ser_context
+    {
+    public:
+        using source_type = Source;
+        using char_type = char;
+        using allocator_type = Allocator;
+    private:
+        basic_msgpack_parser<Source,Allocator> parser_;
+        basic_staj2_visitor<char_type> cursor_visitor_;
+        bool eof_;
+
+        // Noncopyable and nonmoveable
+        basic_msgpack_cursor2(const basic_msgpack_cursor2&) = delete;
+        basic_msgpack_cursor2& operator=(const basic_msgpack_cursor2&) = delete;
+
+    public:
+        using string_view_type = string_view;
+
+        template <class Sourceable>
+        basic_msgpack_cursor2(Sourceable&& source,
+                             const msgpack_decode_options& options = msgpack_decode_options(),
+                             const Allocator& alloc = Allocator())
+            : parser_(std::forward<Sourceable>(source), options, alloc), 
+              cursor_visitor_(accept_all),
+              eof_(false)
+        {
+            if (!done())
+            {
+                next();
+            }
+        }
+
+        // Constructors that set parse error codes
+
+        template <class Sourceable>
+        basic_msgpack_cursor2(Sourceable&& source,
+                             std::error_code& ec)
+           : basic_msgpack_cursor2(std::allocator_arg, Allocator(),
+                                  std::forward<Sourceable>(source), 
+                                  msgpack_decode_options(), 
+                                  ec)
+        {
+        }
+
+        template <class Sourceable>
+        basic_msgpack_cursor2(Sourceable&& source,
+                             const msgpack_decode_options& options,
+                             std::error_code& ec)
+           : basic_msgpack_cursor2(std::allocator_arg, Allocator(),
+                                  std::forward<Sourceable>(source), 
+                                  options, 
+                                  ec)
+        {
+        }
+
+        template <class Sourceable>
+        basic_msgpack_cursor2(std::allocator_arg_t, const Allocator& alloc, 
+                             Sourceable&& source,
+                             const msgpack_decode_options& options,
+                             std::error_code& ec)
+           : parser_(std::forward<Sourceable>(source), options, alloc), 
+             cursor_visitor_(accept_all),
+             eof_(false)
+        {
+            if (!done())
+            {
+                next(ec);
+            }
+        }
+
+        void reset()
+        {
+            parser_.reset();
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next();
+            }
+        }
+
+        template <class Sourceable>
+        void reset(Sourceable&& source)
+        {
+            parser_.reset(std::forward<Sourceable>(source));
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next();
+            }
+        }
+
+        void reset(std::error_code& ec)
+        {
+            parser_.reset();
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next(ec);
+            }
+        }
+
+        template <class Sourceable>
+        void reset(Sourceable&& source, std::error_code& ec)
+        {
+            parser_.reset(std::forward<Sourceable>(source));
+            cursor_visitor_.reset();
+            eof_ = false;
+            if (!done())
+            {
+                next(ec);
+            }
+        }
+
+        bool done() const override
+        {
+            return parser_.done();
+        }
+
+        const staj2_event& current() const override
+        {
+            return cursor_visitor_.event();
+        }
+
+        void read_to(basic_json_visitor2<char_type>& visitor) override
+        {
+            std::error_code ec;
+            read_to(visitor, ec);
+            if (ec)
+            {
+                JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+            }
+        }
+
+        void read_to(basic_json_visitor2<char_type>& visitor,
+                    std::error_code& ec) override
+        {
+            if (cursor_visitor_.dump(visitor, *this, ec))
+            {
+                read_next(visitor, ec);
+            }
+        }
+
+        void next() override
+        {
+            std::error_code ec;
+            next(ec);
+            if (ec)
+            {
+                JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+            }
+        }
+
+        void next(std::error_code& ec) override
+        {
+            read_next(ec);
+        }
+
+        const ser_context& context() const override
+        {
+            return *this;
+        }
+
+        bool eof() const
+        {
+            return eof_;
+        }
+
+        std::size_t line() const override
+        {
+            return parser_.line();
+        }
+
+        std::size_t column() const override
+        {
+            return parser_.column();
+        }
+
+        friend
+        staj2_filter_view operator|(basic_msgpack_cursor2& cursor, 
+                                   std::function<bool(const staj2_event&, const ser_context&)> pred)
+        {
+            return staj2_filter_view(cursor, pred);
+        }
+
+    private:
+        static bool accept_all(const staj2_event&, const ser_context&) 
+        {
+            return true;
+        }
+
+        void read_next(std::error_code& ec)
+        {
+            if (cursor_visitor_.in_available())
+            {
+                cursor_visitor_.send_available(ec);
+            }
+            else
+            {
+                parser_.restart();
+                while (!parser_.stopped())
+                {
+                    parser_.parse(cursor_visitor_, ec);
+                    if (ec) return;
+                }
+            }
+        }
+
+        void read_next(basic_json_visitor2<char_type>& visitor, std::error_code& ec)
+        {
+            {
+                parser_.restart();
+                while (!parser_.stopped())
+                {
+                    parser_.parse(visitor, ec);
+                    if (ec) return;
+                }
+            }
+        }
+    };
+
+    using msgpack_stream_cursor2 = basic_msgpack_cursor2<jsoncons::binary_stream_source>;
+    using msgpack_bytes_cursor2 = basic_msgpack_cursor2<jsoncons::bytes_source>;
+
+} // namespace msgpack
+} // namespace jsoncons
+
+#endif
+
diff --git a/include/jsoncons_ext/msgpack/msgpack_encoder.hpp b/include/jsoncons_ext/msgpack/msgpack_encoder.hpp
new file mode 100644
index 0000000..34e882b
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_encoder.hpp
@@ -0,0 +1,753 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_ENCODER_HPP
+#define JSONCONS_MSGPACK_MSGPACK_ENCODER_HPP
+
+#include <string>
+#include <vector>
+#include <limits> // std::numeric_limits
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/sink.hpp>
+#include <jsoncons/detail/parse_number.hpp>
+#include <jsoncons_ext/msgpack/msgpack_type.hpp>
+#include <jsoncons_ext/msgpack/msgpack_error.hpp>
+#include <jsoncons_ext/msgpack/msgpack_options.hpp>
+
+namespace jsoncons { 
+namespace msgpack {
+
+    enum class msgpack_container_type {object, array};
+
+    template<class Sink=jsoncons::binary_stream_sink,class Allocator=std::allocator<char>>
+    class basic_msgpack_encoder final : public basic_json_visitor<char>
+    {
+        enum class decimal_parse_state { start, integer, exp1, exp2, fraction1 };
+
+        static constexpr int64_t nanos_in_milli = 1000000;
+        static constexpr int64_t nanos_in_second = 1000000000;
+        static constexpr int64_t millis_in_second = 1000;
+    public:
+        using allocator_type = Allocator;
+        using char_type = char;
+        using typename basic_json_visitor<char>::string_view_type;
+        using sink_type = Sink;
+
+    private:
+        struct stack_item
+        {
+            msgpack_container_type type_;
+            std::size_t length_;
+            std::size_t count_;
+
+            stack_item(msgpack_container_type type, std::size_t length = 0) noexcept
+               : type_(type), length_(length), count_(0)
+            {
+            }
+
+            std::size_t length() const
+            {
+                return length_;
+            }
+
+            std::size_t count() const
+            {
+                return count_;
+            }
+
+            bool is_object() const
+            {
+                return type_ == msgpack_container_type::object;
+            }
+        };
+
+        Sink sink_;
+        const msgpack_encode_options options_;
+        allocator_type alloc_;
+
+        std::vector<stack_item> stack_;
+        int nesting_depth_;
+
+        // Noncopyable and nonmoveable
+        basic_msgpack_encoder(const basic_msgpack_encoder&) = delete;
+        basic_msgpack_encoder& operator=(const basic_msgpack_encoder&) = delete;
+    public:
+        explicit basic_msgpack_encoder(Sink&& sink, 
+                                       const Allocator& alloc = Allocator())
+           : basic_msgpack_encoder(std::forward<Sink>(sink), msgpack_encode_options(), alloc)
+        {
+        }
+
+        explicit basic_msgpack_encoder(Sink&& sink, 
+                                       const msgpack_encode_options& options, 
+                                       const Allocator& alloc = Allocator())
+           : sink_(std::forward<Sink>(sink)),
+             options_(options),
+             alloc_(alloc),
+             nesting_depth_(0)
+        {
+        }
+
+        ~basic_msgpack_encoder() noexcept
+        {
+            sink_.flush();
+        }
+
+        void reset()
+        {
+            stack_.clear();
+            nesting_depth_ = 0;
+        }
+
+        void reset(Sink&& sink)
+        {
+            sink_ = std::move(sink);
+            reset();
+        }
+
+    private:
+        // Implementing methods
+
+        void visit_flush() override
+        {
+            sink_.flush();
+        }
+
+        bool visit_begin_object(semantic_tag, const ser_context&, std::error_code& ec) override
+        {
+            ec = msgpack_errc::object_length_required;
+            return false;
+        }
+
+        bool visit_begin_object(std::size_t length, semantic_tag, const ser_context&, std::error_code& ec) override
+        {
+            if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+            {
+                ec = msgpack_errc::max_nesting_depth_exceeded;
+                return false;
+            } 
+            stack_.emplace_back(msgpack_container_type::object, length);
+
+            if (length <= 15)
+            {
+                // fixmap
+                sink_.push_back(jsoncons::msgpack::msgpack_type::fixmap_base_type | (length & 0xf));
+            }
+            else if (length <= 65535)
+            {
+                // map 16
+                sink_.push_back(jsoncons::msgpack::msgpack_type::map16_type);
+                binary::native_to_big(static_cast<uint16_t>(length), 
+                                      std::back_inserter(sink_));
+            }
+            else if (length <= 4294967295)
+            {
+                // map 32
+                sink_.push_back(jsoncons::msgpack::msgpack_type::map32_type);
+                binary::native_to_big(static_cast<uint32_t>(length),
+                                      std::back_inserter(sink_));
+            }
+
+            return true;
+        }
+
+        bool visit_end_object(const ser_context&, std::error_code& ec) override
+        {
+            JSONCONS_ASSERT(!stack_.empty());
+            --nesting_depth_;
+
+            if (stack_.back().count() < stack_.back().length())
+            {
+                ec = msgpack_errc::too_few_items;
+                return false;
+            }
+            else if (stack_.back().count() > stack_.back().length())
+            {
+                ec = msgpack_errc::too_many_items;
+                return false;
+            }
+
+            stack_.pop_back();
+            end_value();
+            return true;
+        }
+
+        bool visit_begin_array(semantic_tag, const ser_context&, std::error_code& ec) override
+        {
+            ec = msgpack_errc::array_length_required;
+            return false;
+        }
+
+        bool visit_begin_array(std::size_t length, semantic_tag, const ser_context&, std::error_code& ec) override
+        {
+            if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+            {
+                ec = msgpack_errc::max_nesting_depth_exceeded;
+                return false;
+            } 
+            stack_.emplace_back(msgpack_container_type::array, length);
+            if (length <= 15)
+            {
+                // fixarray
+                sink_.push_back(jsoncons::msgpack::msgpack_type::fixarray_base_type | (length & 0xf));
+            }
+            else if (length <= (std::numeric_limits<uint16_t>::max)())
+            {
+                // array 16
+                sink_.push_back(jsoncons::msgpack::msgpack_type::array16_type);
+                binary::native_to_big(static_cast<uint16_t>(length),std::back_inserter(sink_));
+            }
+            else if (length <= (std::numeric_limits<uint32_t>::max)())
+            {
+                // array 32
+                sink_.push_back(jsoncons::msgpack::msgpack_type::array32_type);
+                binary::native_to_big(static_cast<uint32_t>(length),std::back_inserter(sink_));
+            }
+            return true;
+        }
+
+        bool visit_end_array(const ser_context&, std::error_code& ec) override
+        {
+            JSONCONS_ASSERT(!stack_.empty());
+
+            --nesting_depth_;
+
+            if (stack_.back().count() < stack_.back().length())
+            {
+                ec = msgpack_errc::too_few_items;
+                return false;
+            }
+            else if (stack_.back().count() > stack_.back().length())
+            {
+                ec = msgpack_errc::too_many_items;
+                return false;
+            }
+
+            stack_.pop_back();
+            end_value();
+            return true;
+        }
+
+        bool visit_key(const string_view_type& name, const ser_context&, std::error_code&) override
+        {
+            write_string_value(name);
+            return true;
+        }
+
+        bool visit_null(semantic_tag, const ser_context&, std::error_code&) override
+        {
+            // nil
+            sink_.push_back(jsoncons::msgpack::msgpack_type::nil_type);
+            end_value();
+            return true;
+        }
+
+        void write_timestamp(int64_t seconds, int64_t nanoseconds)
+        {
+            if ((seconds >> 34) == 0) 
+            {
+                uint64_t data64 = (nanoseconds << 34) | seconds;
+                if ((data64 & 0xffffffff00000000L) == 0) 
+                {
+                    // timestamp 32
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext4_type);
+                    sink_.push_back(0xff);
+                    binary::native_to_big(static_cast<uint32_t>(data64), std::back_inserter(sink_));
+                }
+                else 
+                {
+                    // timestamp 64
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext8_type);
+                    sink_.push_back(0xff);
+                    binary::native_to_big(static_cast<uint64_t>(data64), std::back_inserter(sink_));
+                }
+            }
+            else 
+            {
+                // timestamp 96
+                sink_.push_back(jsoncons::msgpack::msgpack_type::ext8_type);
+                sink_.push_back(0x0c); // 12
+                sink_.push_back(0xff);
+                binary::native_to_big(static_cast<uint32_t>(nanoseconds), std::back_inserter(sink_));
+                binary::native_to_big(static_cast<uint64_t>(seconds), std::back_inserter(sink_));
+            }
+        }
+
+        bool visit_string(const string_view_type& sv, semantic_tag tag, const ser_context&, std::error_code& ec) override
+        {
+            switch (tag)
+            {
+                case semantic_tag::epoch_second:
+                {
+                    int64_t seconds;
+                    auto result = jsoncons::detail::to_integer(sv.data(), sv.length(), seconds);
+                    if (!result)
+                    {
+                        ec = msgpack_errc::invalid_timestamp;
+                        return false;
+                    }
+                    write_timestamp(seconds, 0);
+                    break;
+                }
+                case semantic_tag::epoch_milli:
+                {
+                    bigint n = bigint::from_string(sv.data(), sv.length());
+                    if (n != 0)
+                    {
+                        bigint q;
+                        bigint rem;
+                        n.divide(millis_in_second, q, rem, true);
+                        int64_t seconds = static_cast<int64_t>(q);
+                        int64_t nanoseconds = static_cast<int64_t>(rem) * nanos_in_milli;
+                        if (nanoseconds < 0)
+                        {
+                            nanoseconds = -nanoseconds; 
+                        }
+                        write_timestamp(seconds, nanoseconds);
+                    }
+                    else
+                    {
+                        write_timestamp(0, 0);
+                    }
+                    break;
+                }
+                case semantic_tag::epoch_nano:
+                {
+                    bigint n = bigint::from_string(sv.data(), sv.length());
+                    if (n != 0)
+                    {
+                        bigint q;
+                        bigint rem;
+                        n.divide(nanos_in_second, q, rem, true);
+                        int64_t seconds = static_cast<int64_t>(q);
+                        int64_t nanoseconds = static_cast<int64_t>(rem);
+                        if (nanoseconds < 0)
+                        {
+                            nanoseconds = -nanoseconds; 
+                        }
+                        write_timestamp(seconds, nanoseconds);
+                    }
+                    else
+                    {
+                        write_timestamp(0, 0);
+                    }
+                    break;
+                }
+                default:
+                {
+                    write_string_value(sv);
+                    end_value();
+                    break;
+                }
+            }
+            return true;
+        }
+
+        void write_string_value(const string_view_type& sv) 
+        {
+            auto sink = unicode_traits::validate(sv.data(), sv.size());
+            if (sink.ec != unicode_traits::conv_errc())
+            {
+                JSONCONS_THROW(ser_error(msgpack_errc::invalid_utf8_text_string));
+            }
+
+            const size_t length = sv.length();
+            if (length <= 31)
+            {
+                // fixstr stores a byte array whose length is upto 31 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::fixstr_base_type | static_cast<uint8_t>(length));
+            }
+            else if (length <= (std::numeric_limits<uint8_t>::max)())
+            {
+                // str 8 stores a byte array whose length is upto (2^8)-1 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::str8_type);
+                sink_.push_back(static_cast<uint8_t>(length));
+            }
+            else if (length <= (std::numeric_limits<uint16_t>::max)())
+            {
+                // str 16 stores a byte array whose length is upto (2^16)-1 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::str16_type);
+                binary::native_to_big(static_cast<uint16_t>(length), std::back_inserter(sink_));
+            }
+            else if (length <= (std::numeric_limits<uint32_t>::max)())
+            {
+                // str 32 stores a byte array whose length is upto (2^32)-1 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::str32_type);
+                binary::native_to_big(static_cast<uint32_t>(length),std::back_inserter(sink_));
+            }
+
+            for (auto c : sv)
+            {
+                sink_.push_back(c);
+            }
+        }
+
+        bool visit_byte_string(const byte_string_view& b, 
+                               semantic_tag, 
+                               const ser_context&,
+                               std::error_code&) override
+        {
+
+            const std::size_t length = b.size();
+            if (length <= (std::numeric_limits<uint8_t>::max)())
+            {
+                // bin 8 stores a byte array whose length is upto (2^8)-1 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::bin8_type);
+                sink_.push_back(static_cast<uint8_t>(length));
+            }
+            else if (length <= (std::numeric_limits<uint16_t>::max)())
+            {
+                // bin 16 stores a byte array whose length is upto (2^16)-1 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::bin16_type);
+                binary::native_to_big(static_cast<uint16_t>(length), std::back_inserter(sink_));
+            }
+            else if (length <= (std::numeric_limits<uint32_t>::max)())
+            {
+                // bin 32 stores a byte array whose length is upto (2^32)-1 bytes
+                sink_.push_back(jsoncons::msgpack::msgpack_type::bin32_type);
+                binary::native_to_big(static_cast<uint32_t>(length),std::back_inserter(sink_));
+            }
+
+            for (auto c : b)
+            {
+                sink_.push_back(c);
+            }
+
+            end_value();
+            return true;
+        }
+
+        bool visit_byte_string(const byte_string_view& b, 
+                               uint64_t ext_tag, 
+                               const ser_context&,
+                               std::error_code&) override
+        {
+            const std::size_t length = b.size();
+            switch (length)
+            {
+                case 1:
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext1_type);
+                    sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    break;
+                case 2:
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext2_type);
+                    sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    break;
+                case 4:
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext4_type);
+                    sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    break;
+                case 8:
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext8_type);
+                    sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    break;
+                case 16:
+                    sink_.push_back(jsoncons::msgpack::msgpack_type::fixext16_type);
+                    sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    break;
+                default:
+                    if (length <= (std::numeric_limits<uint8_t>::max)())
+                    {
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::ext8_type);
+                        sink_.push_back(static_cast<uint8_t>(length));
+                        sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    }
+                    else if (length <= (std::numeric_limits<uint16_t>::max)())
+                    {
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::ext16_type);
+                        binary::native_to_big(static_cast<uint16_t>(length), std::back_inserter(sink_));
+                        sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    }
+                    else if (length <= (std::numeric_limits<uint32_t>::max)())
+                    {
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::ext32_type);
+                        binary::native_to_big(static_cast<uint32_t>(length),std::back_inserter(sink_));
+                        sink_.push_back(static_cast<uint8_t>(ext_tag));
+                    }
+                    break;
+            }
+
+            for (auto c : b)
+            {
+                sink_.push_back(c);
+            }
+
+            end_value();
+            return true;
+        }
+
+        bool visit_double(double val, 
+                             semantic_tag,
+                             const ser_context&,
+                             std::error_code&) override
+        {
+            float valf = (float)val;
+            if ((double)valf == val)
+            {
+                // float 32
+                sink_.push_back(jsoncons::msgpack::msgpack_type::float32_type);
+                binary::native_to_big(valf,std::back_inserter(sink_));
+            }
+            else
+            {
+                // float 64
+                sink_.push_back(jsoncons::msgpack::msgpack_type::float64_type);
+                binary::native_to_big(val,std::back_inserter(sink_));
+            }
+
+            // write double
+
+            end_value();
+            return true;
+        }
+
+        bool visit_int64(int64_t val, 
+                         semantic_tag tag, 
+                         const ser_context&,
+                         std::error_code&) override
+        {
+            switch (tag)
+            {
+                case semantic_tag::epoch_second:
+                    write_timestamp(val, 0);
+                    break;
+                case semantic_tag::epoch_milli:
+                {
+                    if (val != 0)
+                    {
+                        auto dv = std::div(val,millis_in_second);
+                        int64_t seconds = dv.quot;
+                        int64_t nanoseconds = dv.rem*nanos_in_milli;
+                        if (nanoseconds < 0)
+                        {
+                            nanoseconds = -nanoseconds; 
+                        }
+                        write_timestamp(seconds, nanoseconds);
+                    }
+                    else
+                    {
+                        write_timestamp(0, 0);
+                    }
+                    break;
+                }
+                case semantic_tag::epoch_nano:
+                {
+                    if (val != 0)
+                    {
+                        auto dv = std::div(val,static_cast<int64_t>(nanos_in_second));
+                        int64_t seconds = dv.quot;
+                        int64_t nanoseconds = dv.rem;
+                        if (nanoseconds < 0)
+                        {
+                            nanoseconds = -nanoseconds; 
+                        }
+                        write_timestamp(seconds, nanoseconds);
+                    }
+                    else
+                    {
+                        write_timestamp(0, 0);
+                    }
+                    break;
+                }
+                default:
+                {
+                    if (val >= 0)
+                    {
+                        if (val <= 0x7f)
+                        {
+                            // positive fixnum stores 7-bit positive integer
+                            sink_.push_back(static_cast<uint8_t>(val));
+                        }
+                        else if (val <= (std::numeric_limits<uint8_t>::max)())
+                        {
+                            // uint 8 stores a 8-bit unsigned integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::uint8_type);
+                            sink_.push_back(static_cast<uint8_t>(val));
+                        }
+                        else if (val <= (std::numeric_limits<uint16_t>::max)())
+                        {
+                            // uint 16 stores a 16-bit big-endian unsigned integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::uint16_type);
+                            binary::native_to_big(static_cast<uint16_t>(val),std::back_inserter(sink_));
+                        }
+                        else if (val <= (std::numeric_limits<uint32_t>::max)())
+                        {
+                            // uint 32 stores a 32-bit big-endian unsigned integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::uint32_type);
+                            binary::native_to_big(static_cast<uint32_t>(val),std::back_inserter(sink_));
+                        }
+                        else if (val <= (std::numeric_limits<int64_t>::max)())
+                        {
+                            // int 64 stores a 64-bit big-endian signed integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::uint64_type);
+                            binary::native_to_big(static_cast<uint64_t>(val),std::back_inserter(sink_));
+                        }
+                    }
+                    else
+                    {
+                        if (val >= -32)
+                        {
+                            // negative fixnum stores 5-bit negative integer
+                            binary::native_to_big(static_cast<int8_t>(val), std::back_inserter(sink_));
+                        }
+                        else if (val >= (std::numeric_limits<int8_t>::lowest)())
+                        {
+                            // int 8 stores a 8-bit signed integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::int8_type);
+                            binary::native_to_big(static_cast<int8_t>(val),std::back_inserter(sink_));
+                        }
+                        else if (val >= (std::numeric_limits<int16_t>::lowest)())
+                        {
+                            // int 16 stores a 16-bit big-endian signed integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::int16_type);
+                            binary::native_to_big(static_cast<int16_t>(val),std::back_inserter(sink_));
+                        }
+                        else if (val >= (std::numeric_limits<int32_t>::lowest)())
+                        {
+                            // int 32 stores a 32-bit big-endian signed integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::int32_type);
+                            binary::native_to_big(static_cast<int32_t>(val),std::back_inserter(sink_));
+                        }
+                        else if (val >= (std::numeric_limits<int64_t>::lowest)())
+                        {
+                            // int 64 stores a 64-bit big-endian signed integer
+                            sink_.push_back(jsoncons::msgpack::msgpack_type::int64_type);
+                            binary::native_to_big(static_cast<int64_t>(val),std::back_inserter(sink_));
+                        }
+                    }
+                }
+                break;
+            }
+            end_value();
+            return true;
+        }
+
+        bool visit_uint64(uint64_t val, 
+                          semantic_tag tag, 
+                          const ser_context&,
+                          std::error_code&) override
+        {
+            switch (tag)
+            {
+                case semantic_tag::epoch_second:
+                    write_timestamp(static_cast<int64_t>(val), 0);
+                    break;
+                case semantic_tag::epoch_milli:
+                {
+                    if (val != 0)
+                    {
+                        auto dv = std::div(static_cast<int64_t>(val), static_cast<int64_t>(millis_in_second));
+                        int64_t seconds = dv.quot;
+                        int64_t nanoseconds = dv.rem*nanos_in_milli;
+                        if (nanoseconds < 0)
+                        {
+                            nanoseconds = -nanoseconds; 
+                        }
+                        write_timestamp(seconds, nanoseconds);
+                    }
+                    else
+                    {
+                        write_timestamp(0, 0);
+                    }
+                    break;
+                }
+                case semantic_tag::epoch_nano:
+                {
+                    if (val != 0)
+                    {
+                        auto dv = std::div(static_cast<int64_t>(val), static_cast<int64_t>(nanos_in_second));
+                        int64_t seconds = dv.quot;
+                        int64_t nanoseconds = dv.rem;
+                        if (nanoseconds < 0)
+                        {
+                            nanoseconds = -nanoseconds; 
+                        }
+                        write_timestamp(seconds, nanoseconds);
+                    }
+                    else
+                    {
+                        write_timestamp(0, 0);
+                    }
+                    break;
+                }
+                default:
+                {
+                    if (val <= static_cast<uint64_t>((std::numeric_limits<int8_t>::max)()))
+                    {
+                        // positive fixnum stores 7-bit positive integer
+                        sink_.push_back(static_cast<uint8_t>(val));
+                    }
+                    else if (val <= (std::numeric_limits<uint8_t>::max)())
+                    {
+                        // uint 8 stores a 8-bit unsigned integer
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::uint8_type);
+                        sink_.push_back(static_cast<uint8_t>(val));
+                    }
+                    else if (val <= (std::numeric_limits<uint16_t>::max)())
+                    {
+                        // uint 16 stores a 16-bit big-endian unsigned integer
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::uint16_type);
+                        binary::native_to_big(static_cast<uint16_t>(val),std::back_inserter(sink_));
+                    }
+                    else if (val <= (std::numeric_limits<uint32_t>::max)())
+                    {
+                        // uint 32 stores a 32-bit big-endian unsigned integer
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::uint32_type);
+                        binary::native_to_big(static_cast<uint32_t>(val),std::back_inserter(sink_));
+                    }
+                    else if (val <= (std::numeric_limits<uint64_t>::max)())
+                    {
+                        // uint 64 stores a 64-bit big-endian unsigned integer
+                        sink_.push_back(jsoncons::msgpack::msgpack_type::uint64_type);
+                        binary::native_to_big(static_cast<uint64_t>(val),std::back_inserter(sink_));
+                    }
+                    break;
+                }
+            }
+            end_value();
+            return true;
+        }
+
+        bool visit_bool(bool val, semantic_tag, const ser_context&, std::error_code&) override
+        {
+            // true and false
+            sink_.push_back(static_cast<uint8_t>(val ? jsoncons::msgpack::msgpack_type::true_type : jsoncons::msgpack::msgpack_type::false_type));
+
+            end_value();
+            return true;
+        }
+
+        void end_value()
+        {
+            if (!stack_.empty())
+            {
+                ++stack_.back().count_;
+            }
+        }
+    };
+
+    using msgpack_stream_encoder = basic_msgpack_encoder<jsoncons::binary_stream_sink>;
+    using msgpack_bytes_encoder = basic_msgpack_encoder<jsoncons::bytes_sink<std::vector<uint8_t>>>;
+
+    #if !defined(JSONCONS_NO_DEPRECATED)
+    JSONCONS_DEPRECATED_MSG("Instead, use msgpack_bytes_encoder") typedef msgpack_bytes_encoder msgpack_bytes_serializer;
+
+    template<class Sink=jsoncons::binary_stream_sink>
+    using basic_msgpack_serializer = basic_msgpack_encoder<Sink>; 
+
+    JSONCONS_DEPRECATED_MSG("Instead, use msgpack_stream_encoder") typedef msgpack_stream_encoder msgpack_encoder;
+    JSONCONS_DEPRECATED_MSG("Instead, use msgpack_stream_encoder") typedef msgpack_stream_encoder msgpack_serializer;
+    JSONCONS_DEPRECATED_MSG("Instead, use msgpack_bytes_encoder") typedef msgpack_bytes_encoder msgpack_buffer_serializer;
+    #endif
+
+} // namespace msgpack
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/msgpack_error.hpp b/include/jsoncons_ext/msgpack/msgpack_error.hpp
new file mode 100644
index 0000000..80c76b6
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_error.hpp
@@ -0,0 +1,94 @@
+/// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_ERROR_HPP
+#define JSONCONS_MSGPACK_MSGPACK_ERROR_HPP
+
+#include <system_error>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace msgpack {
+
+enum class msgpack_errc
+{
+    success = 0,
+    unexpected_eof = 1,
+    source_error,
+    invalid_utf8_text_string,
+    array_length_required,
+    object_length_required,
+    too_many_items,
+    too_few_items,
+    max_nesting_depth_exceeded,
+    length_is_negative,
+    invalid_timestamp,
+    unknown_type
+};
+
+class msgpack_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/msgpack";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<msgpack_errc>(ev))
+        {
+            case msgpack_errc::unexpected_eof:
+                return "Unexpected end of file";
+            case msgpack_errc::source_error:
+                return "Source error";
+            case msgpack_errc::invalid_utf8_text_string:
+                return "Illegal UTF-8 encoding in text string";
+            case msgpack_errc::array_length_required:
+                return "MessagePack encoder requires array length";
+            case msgpack_errc::object_length_required:
+                return "MessagePack encoder requires object length";
+            case msgpack_errc::too_many_items:
+                return "Too many items were added to a MessagePack object or array";
+            case msgpack_errc::too_few_items:
+                return "Too few items were added to a MessagePack object or array";
+            case msgpack_errc::max_nesting_depth_exceeded:
+                return "Data item nesting exceeds limit in options";
+            case msgpack_errc::length_is_negative:
+                return "Request for the length of an array, map or string returned a negative result";
+            case msgpack_errc::invalid_timestamp:
+                return "Invalid timestamp";
+            case msgpack_errc::unknown_type:
+                return "An unknown type was found in the stream";
+            default:
+                return "Unknown MessagePack parser error";
+        }
+    }
+};
+
+inline
+const std::error_category& msgpack_error_category()
+{
+  static msgpack_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(msgpack_errc e)
+{
+    return std::error_code(static_cast<int>(e),msgpack_error_category());
+}
+
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::msgpack::msgpack_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/msgpack_options.hpp b/include/jsoncons_ext/msgpack/msgpack_options.hpp
new file mode 100644
index 0000000..17bddf1
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_options.hpp
@@ -0,0 +1,74 @@
+// Copyright 2019 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_OPTIONS_HPP
+#define JSONCONS_MSGPACK_MSGPACK_OPTIONS_HPP
+
+#include <string>
+#include <limits> // std::numeric_limits
+#include <cwchar>
+#include <jsoncons/json_exception.hpp>
+
+namespace jsoncons { namespace msgpack {
+
+class msgpack_options;
+
+class msgpack_options_common
+{
+    friend class msgpack_options;
+
+    int max_nesting_depth_;
+protected:
+    virtual ~msgpack_options_common() = default;
+
+    msgpack_options_common()
+        : max_nesting_depth_(1024)
+    {
+    }
+
+    msgpack_options_common(const msgpack_options_common&) = default;
+    msgpack_options_common& operator=(const msgpack_options_common&) = default;
+    msgpack_options_common(msgpack_options_common&&) = default;
+    msgpack_options_common& operator=(msgpack_options_common&&) = default;
+public:
+    int max_nesting_depth() const 
+    {
+        return max_nesting_depth_;
+    }
+};
+
+class msgpack_decode_options : public virtual msgpack_options_common
+{
+    friend class msgpack_options;
+public:
+    msgpack_decode_options()
+    {
+    }
+};
+
+class msgpack_encode_options : public virtual msgpack_options_common
+{
+    friend class msgpack_options;
+public:
+    msgpack_encode_options()
+    {
+    }
+};
+
+class msgpack_options final : public msgpack_decode_options, public msgpack_encode_options
+{
+public:
+    using msgpack_options_common::max_nesting_depth;
+
+    msgpack_options& max_nesting_depth(int value)
+    {
+        this->max_nesting_depth_ = value;
+        return *this;
+    }
+};
+
+}}
+#endif
diff --git a/include/jsoncons_ext/msgpack/msgpack_parser.hpp b/include/jsoncons_ext/msgpack/msgpack_parser.hpp
new file mode 100644
index 0000000..cf2d507
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_parser.hpp
@@ -0,0 +1,748 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_PARSER_HPP
+#define JSONCONS_MSGPACK_MSGPACK_PARSER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/bigint.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/msgpack/msgpack_type.hpp>
+#include <jsoncons_ext/msgpack/msgpack_error.hpp>
+#include <jsoncons_ext/msgpack/msgpack_options.hpp>
+#include <jsoncons/json_visitor2.hpp>
+
+namespace jsoncons { namespace msgpack {
+
+enum class parse_mode {root,accept,array,map_key,map_value};
+
+struct parse_state 
+{
+    parse_mode mode; 
+    std::size_t length;
+    std::size_t index;
+
+    parse_state(parse_mode mode, std::size_t length) noexcept
+        : mode(mode), length(length), index(0)
+    {
+    }
+
+    parse_state(const parse_state&) = default;
+    parse_state(parse_state&&) = default;
+};
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_msgpack_parser : public ser_context
+{
+    using char_type = char;
+    using char_traits_type = std::char_traits<char>;
+    using temp_allocator_type = Allocator;
+    using char_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<char_type>;                  
+    using byte_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<uint8_t>;                  
+    using int64_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<int64_t>;                  
+    using parse_state_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<parse_state>;                         
+
+    static constexpr int64_t nanos_in_second = 1000000000;
+
+    Source source_;
+    msgpack_decode_options options_;
+    bool more_;
+    bool done_;
+    std::basic_string<char,std::char_traits<char>,char_allocator_type> text_buffer_;
+    std::vector<uint8_t,byte_allocator_type> bytes_buffer_;
+    std::vector<parse_state,parse_state_allocator_type> state_stack_;
+    int nesting_depth_;
+
+public:
+    template <class Sourceable>
+    basic_msgpack_parser(Sourceable&& source,
+                         const msgpack_decode_options& options = msgpack_decode_options(),
+                         const Allocator alloc = Allocator())
+       : source_(std::forward<Sourceable>(source)),
+         options_(options),
+         more_(true), 
+         done_(false),
+         text_buffer_(alloc),
+         bytes_buffer_(alloc),
+         state_stack_(alloc),
+         nesting_depth_(0)
+    {
+        state_stack_.emplace_back(parse_mode::root,0);
+    }
+
+    void restart()
+    {
+        more_ = true;
+    }
+
+    void reset()
+    {
+        more_ = true;
+        done_ = false;
+        text_buffer_.clear();
+        bytes_buffer_.clear();
+        state_stack_.clear();
+        state_stack_.emplace_back(parse_mode::root,0);
+        nesting_depth_ = 0;
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        source_ = std::forward<Sourceable>(source);
+        reset();
+    }
+
+    bool done() const
+    {
+        return done_;
+    }
+
+    bool stopped() const
+    {
+        return !more_;
+    }
+
+    std::size_t line() const override
+    {
+        return 0;
+    }
+
+    std::size_t column() const override
+    {
+        return source_.position();
+    }
+
+    void parse(json_visitor2& visitor, std::error_code& ec)
+    {
+        while (!done_ && more_)
+        {
+            switch (state_stack_.back().mode)
+            {
+                case parse_mode::array:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        read_item(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        end_array(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::map_key:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        state_stack_.back().mode = parse_mode::map_value;
+                        read_item(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        end_object(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::map_value:
+                {
+                    state_stack_.back().mode = parse_mode::map_key;
+                    read_item(visitor, ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    break;
+                }
+                case parse_mode::root:
+                {
+                    state_stack_.back().mode = parse_mode::accept;
+                    read_item(visitor, ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    break;
+                }
+                case parse_mode::accept:
+                {
+                    JSONCONS_ASSERT(state_stack_.size() == 1);
+                    state_stack_.clear();
+                    more_ = false;
+                    done_ = true;
+                    visitor.flush();
+                    break;
+                }
+            }
+        }
+    }
+private:
+
+    void read_item(json_visitor2& visitor, std::error_code& ec)
+    {
+        if (source_.is_error())
+        {
+            ec = msgpack_errc::source_error;
+            more_ = false;
+            return;
+        }   
+
+        uint8_t type;
+        if (source_.read(&type, 1) == 0)
+        {
+            ec = msgpack_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+
+        if (type <= 0xbf)
+        {
+            if (type <= 0x7f) 
+            {
+                // positive fixint
+                more_ = visitor.uint64_value(type, semantic_tag::none, *this, ec);
+            }
+            else if (type <= 0x8f) 
+            {
+                begin_object(visitor,type,ec); // fixmap
+            }
+            else if (type <= 0x9f) 
+            {
+                begin_array(visitor,type,ec); // fixarray
+            }
+            else 
+            {
+                // fixstr
+                const size_t len = type & 0x1f;
+
+                text_buffer_.clear();
+
+                if (source_reader<Source>::read(source_,text_buffer_,len) != static_cast<std::size_t>(len))
+                {
+                    ec = msgpack_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+
+                auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+                if (result.ec != unicode_traits::conv_errc())
+                {
+                    ec = msgpack_errc::invalid_utf8_text_string;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.string_value(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), semantic_tag::none, *this, ec);
+            }
+        }
+        else if (type >= 0xe0) 
+        {
+            // negative fixint
+            more_ = visitor.int64_value(static_cast<int8_t>(type), semantic_tag::none, *this, ec);
+        }
+        else
+        {
+            switch (type)
+            {
+                case jsoncons::msgpack::msgpack_type::nil_type: 
+                {
+                    more_ = visitor.null_value(semantic_tag::none, *this, ec);
+                    break;
+                }
+                case jsoncons::msgpack::msgpack_type::true_type:
+                {
+                    more_ = visitor.bool_value(true, semantic_tag::none, *this, ec);
+                    break;
+                }
+                case jsoncons::msgpack::msgpack_type::false_type:
+                {
+                    more_ = visitor.bool_value(false, semantic_tag::none, *this, ec);
+                    break;
+                }
+                case jsoncons::msgpack::msgpack_type::float32_type: 
+                {
+                    uint8_t buf[sizeof(float)];
+                    if (source_.read(buf, sizeof(float)) != sizeof(float))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    float val = binary::big_to_native<float>(buf, sizeof(buf));
+                    more_ = visitor.double_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::float64_type: 
+                {
+                    uint8_t buf[sizeof(double)];
+                    if (source_.read(buf, sizeof(double)) != sizeof(double))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    double val = binary::big_to_native<double>(buf, sizeof(buf));
+                    more_ = visitor.double_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::uint8_type: 
+                {
+                    uint8_t b;
+                    if (source_.read(&b, 1) == 0)
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    more_ = visitor.uint64_value(b, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::uint16_type: 
+                {
+                    uint8_t buf[sizeof(uint16_t)];
+                    if (source_.read(buf, sizeof(uint16_t)) !=sizeof(uint16_t)) 
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    uint16_t val = binary::big_to_native<uint16_t>(buf, sizeof(buf));
+                    more_ = visitor.uint64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::uint32_type: 
+                {
+                    uint8_t buf[sizeof(uint32_t)];
+                    if (source_.read(buf, sizeof(uint32_t)) != sizeof(uint32_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    uint32_t val = binary::big_to_native<uint32_t>(buf, sizeof(buf));
+                    more_ = visitor.uint64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::uint64_type: 
+                {
+                    uint8_t buf[sizeof(uint64_t)];
+                    if (source_.read(buf, sizeof(uint64_t)) != sizeof(uint64_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    uint64_t val = binary::big_to_native<uint64_t>(buf, sizeof(buf));
+                    more_ = visitor.uint64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::int8_type: 
+                {
+                    uint8_t buf[sizeof(int8_t)];
+                    if (source_.read(buf, sizeof(int8_t)) != sizeof(int8_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    int8_t val = binary::big_to_native<int8_t>(buf, sizeof(buf));
+                    more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::int16_type: 
+                {
+                    uint8_t buf[sizeof(int16_t)];
+                    if (source_.read(buf, sizeof(int16_t)) != sizeof(int16_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    int16_t val = binary::big_to_native<int16_t>(buf, sizeof(buf));
+                    more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::int32_type: 
+                {
+                    uint8_t buf[sizeof(int32_t)];
+                    if (source_.read(buf, sizeof(int32_t)) != sizeof(int32_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    int32_t val = binary::big_to_native<int32_t>(buf, sizeof(buf));
+                    more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::int64_type: 
+                {
+                    uint8_t buf[sizeof(int64_t)];
+                    if (source_.read(buf, sizeof(int64_t)) != sizeof(int64_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    int64_t val = binary::big_to_native<int64_t>(buf, sizeof(buf));
+                    more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::str8_type: 
+                case jsoncons::msgpack::msgpack_type::str16_type: 
+                case jsoncons::msgpack::msgpack_type::str32_type: 
+                {
+                    std::size_t len = get_size(type, ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+
+                    text_buffer_.clear();
+                    if (source_reader<Source>::read(source_,text_buffer_,len) != static_cast<std::size_t>(len))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+
+                    auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+                    if (result.ec != unicode_traits::conv_errc())
+                    {
+                        ec = msgpack_errc::invalid_utf8_text_string;
+                        more_ = false;
+                        return;
+                    }
+                    more_ = visitor.string_value(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), semantic_tag::none, *this, ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::bin8_type: 
+                case jsoncons::msgpack::msgpack_type::bin16_type: 
+                case jsoncons::msgpack::msgpack_type::bin32_type: 
+                {
+                    std::size_t len = get_size(type,ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+                    bytes_buffer_.clear();
+                    if (source_reader<Source>::read(source_,bytes_buffer_,len) != static_cast<std::size_t>(len))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+
+                    more_ = visitor.byte_string_value(byte_string_view(bytes_buffer_.data(),bytes_buffer_.size()), 
+                                                      semantic_tag::none, 
+                                                      *this,
+                                                      ec);
+                    break;
+                }
+                case jsoncons::msgpack::msgpack_type::fixext1_type: 
+                case jsoncons::msgpack::msgpack_type::fixext2_type: 
+                case jsoncons::msgpack::msgpack_type::fixext4_type: 
+                case jsoncons::msgpack::msgpack_type::fixext8_type: 
+                case jsoncons::msgpack::msgpack_type::fixext16_type: 
+                case jsoncons::msgpack::msgpack_type::ext8_type: 
+                case jsoncons::msgpack::msgpack_type::ext16_type: 
+                case jsoncons::msgpack::msgpack_type::ext32_type: 
+                {
+                    std::size_t len = get_size(type,ec);
+                    if (!more_)
+                    {
+                        return;
+                    }
+
+                    // type
+                    uint8_t buf[sizeof(int8_t)];
+                    if (source_.read(buf, sizeof(int8_t)) != sizeof(int8_t))
+                    {
+                        ec = msgpack_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+
+                    int8_t ext_type = binary::big_to_native<int8_t>(buf, sizeof(buf));
+
+                    bool is_timestamp = false; 
+                    if (ext_type == -1)
+                    {
+                        is_timestamp = true;;
+                    }
+
+                    // payload
+                    if (is_timestamp && len == 4)
+                    {
+                        uint8_t buf32[sizeof(uint32_t)];
+                        if (source_.read(buf32, sizeof(uint32_t)) != sizeof(uint32_t))
+                        {
+                            ec = msgpack_errc::unexpected_eof;
+                            more_ = false;
+                            return;
+                        }
+                        uint32_t val = binary::big_to_native<uint32_t>(buf32, sizeof(buf32));
+                        more_ = visitor.uint64_value(val, semantic_tag::epoch_second, *this, ec);
+                    }
+                    else if (is_timestamp && len == 8)
+                    {
+                        uint8_t buf64[sizeof(uint64_t)];
+                        if (source_.read(buf64, sizeof(uint64_t)) != sizeof(uint64_t))
+                        {
+                            ec = msgpack_errc::unexpected_eof;
+                            more_ = false;
+                            return;
+                        }
+                        uint64_t data64 = binary::big_to_native<uint64_t>(buf64, sizeof(buf64));
+                        uint64_t sec = data64 & 0x00000003ffffffffL;
+                        uint64_t nsec = data64 >> 34;
+
+                        bigint nano(sec);
+                        nano *= uint64_t(nanos_in_second);
+                        nano += nsec;
+                        text_buffer_.clear();
+                        nano.write_string(text_buffer_);
+                        more_ = visitor.string_value(text_buffer_, semantic_tag::epoch_nano, *this, ec);
+                        if (!more_) return;
+                    }
+                    else if (is_timestamp && len == 12)
+                    {
+                        uint8_t buf1[sizeof(uint32_t)];
+                        if (source_.read(buf1, sizeof(uint32_t)) != sizeof(uint32_t))
+                        {
+                            ec = msgpack_errc::unexpected_eof;
+                            more_ = false;
+                            return;
+                        }
+                        uint32_t nsec = binary::big_to_native<uint32_t>(buf1, sizeof(buf1));
+
+                        uint8_t buf2[sizeof(int64_t)];
+                        if (source_.read(buf2, sizeof(int64_t)) != sizeof(int64_t))
+                        {
+                            ec = msgpack_errc::unexpected_eof;
+                            more_ = false;
+                            return;
+                        }
+                        int64_t sec = binary::big_to_native<int64_t>(buf2, sizeof(buf2));
+
+                        bigint nano(sec);
+
+                        nano *= uint64_t(nanos_in_second);
+
+                        if (nano < 0)
+                        {
+                            nano -= nsec;
+                        }
+                        else
+                        {
+                            nano += nsec;
+                        }
+
+                        text_buffer_.clear();
+                        nano.write_string(text_buffer_);
+                        more_ = visitor.string_value(text_buffer_, semantic_tag::epoch_nano, *this, ec);
+                        if (!more_) return;
+                    }
+                    else
+                    {
+                        bytes_buffer_.clear();
+                        if (source_reader<Source>::read(source_,bytes_buffer_,len) != static_cast<std::size_t>(len))
+                        {
+                            ec = msgpack_errc::unexpected_eof;
+                            more_ = false;
+                            return;
+                        }
+
+                        more_ = visitor.byte_string_value(byte_string_view(bytes_buffer_.data(),bytes_buffer_.size()), 
+                                                          static_cast<uint8_t>(ext_type), 
+                                                          *this,
+                                                          ec);
+                    }
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::array16_type: 
+                case jsoncons::msgpack::msgpack_type::array32_type: 
+                {
+                    begin_array(visitor,type,ec);
+                    break;
+                }
+
+                case jsoncons::msgpack::msgpack_type::map16_type : 
+                case jsoncons::msgpack::msgpack_type::map32_type : 
+                {
+                    begin_object(visitor, type, ec);
+                    break;
+                }
+
+                default:
+                {
+                    ec = msgpack_errc::unknown_type;
+                    more_ = false;
+                    return;
+                }
+            }
+        }
+    }
+
+    void begin_array(json_visitor2& visitor, uint8_t type, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = msgpack_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+        std::size_t length = get_size(type, ec);
+        if (!more_)
+        {
+            return;
+        }
+        state_stack_.emplace_back(parse_mode::array,length);
+        more_ = visitor.begin_array(length, semantic_tag::none, *this, ec);
+    }
+
+    void end_array(json_visitor2& visitor, std::error_code& ec)
+    {
+        --nesting_depth_;
+
+        more_ = visitor.end_array(*this, ec);
+        state_stack_.pop_back();
+    }
+
+    void begin_object(json_visitor2& visitor, uint8_t type, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = msgpack_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+        std::size_t length = get_size(type, ec);
+        if (!more_)
+        {
+            return;
+        }
+        state_stack_.emplace_back(parse_mode::map_key,length);
+        more_ = visitor.begin_object(length, semantic_tag::none, *this, ec);
+    }
+
+    void end_object(json_visitor2& visitor, std::error_code& ec)
+    {
+        --nesting_depth_;
+        more_ = visitor.end_object(*this, ec);
+        state_stack_.pop_back();
+    }
+
+    std::size_t get_size(uint8_t type, std::error_code& ec)
+    {
+        switch (type)
+        {
+            case jsoncons::msgpack::msgpack_type::str8_type: 
+            case jsoncons::msgpack::msgpack_type::bin8_type: 
+            case jsoncons::msgpack::msgpack_type::ext8_type: 
+            {
+                uint8_t buf[sizeof(int8_t)];
+                if (source_.read(buf, sizeof(int8_t)) != sizeof(int8_t))
+                {
+                    ec = msgpack_errc::unexpected_eof;
+                    more_ = false;
+                    return 0;
+                }
+                uint8_t len = binary::big_to_native<uint8_t>(buf, sizeof(buf));
+                return static_cast<std::size_t>(len);
+            }
+
+            case jsoncons::msgpack::msgpack_type::str16_type: 
+            case jsoncons::msgpack::msgpack_type::bin16_type: 
+            case jsoncons::msgpack::msgpack_type::ext16_type: 
+            case jsoncons::msgpack::msgpack_type::array16_type: 
+            case jsoncons::msgpack::msgpack_type::map16_type:
+            {
+                uint8_t buf[sizeof(int16_t)];
+                if (source_.read(buf, sizeof(int16_t)) != sizeof(int16_t))
+                {
+                    ec = msgpack_errc::unexpected_eof;
+                    more_ = false;
+                    return 0;
+                }
+                uint16_t len = binary::big_to_native<uint16_t>(buf, sizeof(buf));
+                return static_cast<std::size_t>(len);
+            }
+
+            case jsoncons::msgpack::msgpack_type::str32_type: 
+            case jsoncons::msgpack::msgpack_type::bin32_type: 
+            case jsoncons::msgpack::msgpack_type::ext32_type: 
+            case jsoncons::msgpack::msgpack_type::array32_type: 
+            case jsoncons::msgpack::msgpack_type::map32_type : 
+            {
+                uint8_t buf[sizeof(int32_t)];
+                if (source_.read(buf, sizeof(int32_t)) != sizeof(int32_t))
+                {
+                    ec = msgpack_errc::unexpected_eof;
+                    more_ = false;
+                    return 0;
+                }
+                uint32_t len = binary::big_to_native<uint32_t>(buf, sizeof(buf));
+                return static_cast<std::size_t>(len);
+            }
+            case jsoncons::msgpack::msgpack_type::fixext1_type: 
+                return 1;
+            case jsoncons::msgpack::msgpack_type::fixext2_type: 
+                return 2;
+            case jsoncons::msgpack::msgpack_type::fixext4_type: 
+                return 4;
+            case jsoncons::msgpack::msgpack_type::fixext8_type: 
+                return 8;
+            case jsoncons::msgpack::msgpack_type::fixext16_type: 
+                return 16;
+            default:
+                if ((type > 0x8f && type <= 0x9f) // fixarray
+                    || (type > 0x7f && type <= 0x8f) // fixmap
+                   )
+                {
+                    return type & 0x0f;
+                }
+                else
+                {
+                    ec = msgpack_errc::unknown_type;
+                    more_ = false;
+                    return 0;
+                }
+                break;
+        }
+    }
+};
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/msgpack_reader.hpp b/include/jsoncons_ext/msgpack/msgpack_reader.hpp
new file mode 100644
index 0000000..c0d788a
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_reader.hpp
@@ -0,0 +1,116 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_READER_HPP
+#define JSONCONS_MSGPACK_MSGPACK_READER_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/msgpack/msgpack_type.hpp>
+#include <jsoncons_ext/msgpack/msgpack_error.hpp>
+#include <jsoncons_ext/msgpack/msgpack_parser.hpp>
+
+namespace jsoncons { namespace msgpack {
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_msgpack_reader
+{
+    using char_type = char;
+
+    basic_msgpack_parser<Source,Allocator> parser_;
+    basic_json_visitor2_to_visitor_adaptor<char_type,Allocator> adaptor_;
+    json_visitor2& visitor_;
+public:
+    template <class Sourceable>
+    basic_msgpack_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const Allocator alloc)
+       : basic_msgpack_reader(std::forward<Sourceable>(source),
+                           visitor,
+                           msgpack_decode_options(),
+                           alloc)
+    {
+    }
+
+    template <class Sourceable>
+    basic_msgpack_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const msgpack_decode_options& options = msgpack_decode_options(),
+                      const Allocator alloc=Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         adaptor_(visitor, alloc), visitor_(adaptor_)
+    {
+    }
+    template <class Sourceable>
+    basic_msgpack_reader(Sourceable&& source, 
+                      json_visitor2& visitor, 
+                      const Allocator alloc)
+       : basic_msgpack_reader(std::forward<Sourceable>(source),
+                           visitor,
+                           msgpack_decode_options(),
+                           alloc)
+    {
+    }
+
+    template <class Sourceable>
+    basic_msgpack_reader(Sourceable&& source, 
+                      json_visitor2& visitor, 
+                      const msgpack_decode_options& options = msgpack_decode_options(),
+                      const Allocator alloc=Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         visitor_(visitor)
+    {
+    }
+
+    void read()
+    {
+        std::error_code ec;
+        read(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,line(),column()));
+        }
+    }
+
+    void read(std::error_code& ec)
+    {
+        parser_.reset();
+        parser_.parse(visitor_, ec);
+        if (ec)
+        {
+            return;
+        }
+    }
+
+    std::size_t line() const 
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const 
+    {
+        return parser_.column();
+    }
+};
+
+using msgpack_stream_reader = basic_msgpack_reader<jsoncons::binary_stream_source>;
+
+using msgpack_bytes_reader = basic_msgpack_reader<jsoncons::bytes_source>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+JSONCONS_DEPRECATED_MSG("Instead, use msgpack_stream_reader") typedef msgpack_stream_reader msgpack_reader;
+JSONCONS_DEPRECATED_MSG("Instead, use msgpack_bytes_reader") typedef msgpack_bytes_reader msgpack_buffer_reader;
+#endif
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/msgpack/msgpack_type.hpp b/include/jsoncons_ext/msgpack/msgpack_type.hpp
new file mode 100644
index 0000000..aa9f8fd
--- /dev/null
+++ b/include/jsoncons_ext/msgpack/msgpack_type.hpp
@@ -0,0 +1,63 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_MSGPACK_MSGPACK_TYPE_HPP
+#define JSONCONS_MSGPACK_MSGPACK_TYPE_HPP
+
+#include <string>
+#include <memory>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace msgpack {
+
+    namespace msgpack_type
+    {
+        const uint8_t positive_fixint_base_type = 0x00;
+        const uint8_t nil_type = 0xc0;
+        const uint8_t false_type = 0xc2;
+        const uint8_t true_type = 0xc3;
+        const uint8_t float32_type = 0xca;
+        const uint8_t float64_type = 0xcb;
+        const uint8_t uint8_type = 0xcc;
+        const uint8_t uint16_type = 0xcd;
+        const uint8_t uint32_type = 0xce;
+        const uint8_t uint64_type = 0xcf;
+        const uint8_t int8_type = 0xd0;
+        const uint8_t int16_type = 0xd1;
+        const uint8_t int32_type = 0xd2;
+        const uint8_t int64_type = 0xd3;
+
+        const uint8_t fixmap_base_type = 0x80;
+        const uint8_t fixarray_base_type = 0x90;
+        const uint8_t fixstr_base_type = 0xa0;
+        const uint8_t str8_type = 0xd9;
+        const uint8_t str16_type = 0xda;
+        const uint8_t str32_type = 0xdb;
+
+        const uint8_t bin8_type = 0xc4; //  0xC4
+        const uint8_t bin16_type = 0xc5;
+        const uint8_t bin32_type = 0xc6;
+
+        const uint8_t fixext1_type = 0xd4;
+        const uint8_t fixext2_type = 0xd5;
+        const uint8_t fixext4_type = 0xd6;
+        const uint8_t fixext8_type = 0xd7;
+        const uint8_t fixext16_type = 0xd8;
+        const uint8_t ext8_type = 0xc7; //  0xC4
+        const uint8_t ext16_type = 0xc8;
+        const uint8_t ext32_type = 0xc9;
+
+        const uint8_t array16_type = 0xdc;
+        const uint8_t array32_type = 0xdd;
+        const uint8_t map16_type = 0xde;
+        const uint8_t map32_type = 0xdf;
+        const uint8_t negative_fixint_base_type = 0xe0;
+    }
+ 
+} // namespace msgpack
+} // namespace jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/decode_ubjson.hpp b/include/jsoncons_ext/ubjson/decode_ubjson.hpp
new file mode 100644
index 0000000..91c9c0f
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/decode_ubjson.hpp
@@ -0,0 +1,201 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_DECODE_UBJSON_HPP
+#define JSONCONS_UBJSON_DECODE_UBJSON_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/ubjson/ubjson_reader.hpp>
+#include <jsoncons_ext/ubjson/ubjson_cursor.hpp>
+
+namespace jsoncons { 
+namespace ubjson {
+
+    template<class T, class Source>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_ubjson(const Source& v, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_ubjson_reader<jsoncons::bytes_source> reader(v, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_ubjson(const Source& v, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        basic_ubjson_cursor<bytes_source> cursor(v, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_ubjson(std::istream& is, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        ubjson_stream_reader reader(is, adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_ubjson(std::istream& is, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        basic_ubjson_cursor<binary_stream_source> cursor(is, options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_ubjson(InputIt first, InputIt last,
+                const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        jsoncons::json_decoder<T> decoder;
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_ubjson_reader<binary_iterator_source<InputIt>> reader(binary_iterator_source<InputIt>(first, last), adaptor, options);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class InputIt>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_ubjson(InputIt first, InputIt last,
+                const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        basic_ubjson_cursor<binary_iterator_source<InputIt>> cursor(binary_iterator_source<InputIt>(first, last), options);
+        json_decoder<basic_json<char,sorted_policy>> decoder{};
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    // With leading allocator parameter
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                  const Source& v, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_ubjson_reader<jsoncons::bytes_source,TempAllocator> reader(v, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T, class Source, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_byte_sequence<Source>::value,T>::type 
+    decode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                  const Source& v, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        basic_ubjson_cursor<bytes_source,TempAllocator> cursor(v, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,T>::type 
+    decode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                  std::istream& is, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        json_decoder<T,TempAllocator> decoder(temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<json_visitor>(decoder);
+        basic_ubjson_reader<jsoncons::binary_stream_source,TempAllocator> reader(is, adaptor, options, temp_alloc);
+        reader.read();
+        if (!decoder.is_valid())
+        {
+            JSONCONS_THROW(ser_error(conv_errc::conversion_failed, reader.line(), reader.column()));
+        }
+        return decoder.get_result();
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,T>::type 
+    decode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                  std::istream& is, 
+                  const ubjson_decode_options& options = ubjson_decode_options())
+    {
+        basic_ubjson_cursor<binary_stream_source,TempAllocator> cursor(is, options, temp_alloc);
+        json_decoder<basic_json<char,sorted_policy,TempAllocator>,TempAllocator> decoder(temp_alloc, temp_alloc);
+
+        std::error_code ec;
+        T val = decode_traits<T,char>::decode(cursor, decoder, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec, cursor.context().line(), cursor.context().column()));
+        }
+        return val;
+    }
+
+} // ubjson
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/encode_ubjson.hpp b/include/jsoncons_ext/ubjson/encode_ubjson.hpp
new file mode 100644
index 0000000..e8a244b
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/encode_ubjson.hpp
@@ -0,0 +1,142 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_ENCODE_UBJSON_HPP
+#define JSONCONS_UBJSON_ENCODE_UBJSON_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/ubjson/ubjson_encoder.hpp>
+#include <jsoncons_ext/ubjson/ubjson_reader.hpp>
+
+namespace jsoncons { 
+namespace ubjson {
+
+    template<class T, class Container>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_ubjson(const T& j, 
+                  Container& v, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_ubjson_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_ubjson(const T& val, 
+                  Container& v, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        basic_ubjson_encoder<jsoncons::bytes_sink<Container>> encoder(v, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template<class T>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_ubjson(const T& j, 
+                  std::ostream& os, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        ubjson_stream_encoder encoder(os, options);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_ubjson(const T& val, 
+                  std::ostream& os, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        ubjson_stream_encoder encoder(os, options);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    // with temp_allocator_arg_t
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,const T& j, 
+                  Container& v, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_ubjson_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T, class Container, class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value &&
+                            type_traits::is_back_insertable_byte_container<Container>::value,void>::type 
+    encode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,const T& val, 
+                  Container& v, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        basic_ubjson_encoder<jsoncons::bytes_sink<Container>,TempAllocator> encoder(v, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<type_traits::is_basic_json<T>::value,void>::type 
+    encode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                  const T& j, 
+                  std::ostream& os, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        using char_type = typename T::char_type;
+        basic_ubjson_encoder<jsoncons::binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        auto adaptor = make_json_visitor_adaptor<basic_json_visitor<char_type>>(encoder);
+        j.dump(adaptor);
+    }
+
+    template<class T,class TempAllocator>
+    typename std::enable_if<!type_traits::is_basic_json<T>::value,void>::type 
+    encode_ubjson(temp_allocator_arg_t, const TempAllocator& temp_alloc,
+                  const T& val, 
+                  std::ostream& os, 
+                  const ubjson_encode_options& options = ubjson_encode_options())
+    {
+        basic_ubjson_encoder<jsoncons::binary_stream_sink,TempAllocator> encoder(os, options, temp_alloc);
+        std::error_code ec;
+        encode_traits<T,char>::encode(val, encoder, json(), ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec));
+        }
+    }
+
+} // ubjson
+} // jsoncons
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson.hpp b/include/jsoncons_ext/ubjson/ubjson.hpp
new file mode 100644
index 0000000..c2729bd
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson.hpp
@@ -0,0 +1,23 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_HPP
+#define JSONCONS_UBJSON_UBJSON_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::enable_if
+#include <istream> // std::basic_istream
+#include <jsoncons/json.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/ubjson/ubjson_encoder.hpp>
+#include <jsoncons_ext/ubjson/ubjson_reader.hpp>
+#include <jsoncons_ext/ubjson/ubjson_cursor.hpp>
+#include <jsoncons_ext/ubjson/encode_ubjson.hpp>
+#include <jsoncons_ext/ubjson/decode_ubjson.hpp>
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson_cursor.hpp b/include/jsoncons_ext/ubjson/ubjson_cursor.hpp
new file mode 100644
index 0000000..f60825e
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_cursor.hpp
@@ -0,0 +1,307 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_CURSOR_HPP
+#define JSONCONS_UBJSON_UBJSON_CURSOR_HPP
+
+#include <memory> // std::allocator
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <ios>
+#include <istream> // std::basic_istream
+#include <jsoncons/byte_string.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/staj_cursor.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons_ext/ubjson/ubjson_parser.hpp>
+
+namespace jsoncons { 
+namespace ubjson {
+
+template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>>
+class basic_ubjson_cursor : public basic_staj_cursor<char>, private virtual ser_context
+{
+public:
+    using source_type = Source;
+    using char_type = char;
+    using allocator_type = Allocator;
+private:
+    basic_ubjson_parser<Source,Allocator> parser_;
+    basic_staj_visitor<char_type> cursor_visitor_;
+    bool eof_;
+
+    // Noncopyable and nonmoveable
+    basic_ubjson_cursor(const basic_ubjson_cursor&) = delete;
+    basic_ubjson_cursor& operator=(const basic_ubjson_cursor&) = delete;
+
+public:
+    using string_view_type = string_view;
+
+    template <class Sourceable>
+    basic_ubjson_cursor(Sourceable&& source,
+                      const ubjson_decode_options& options = ubjson_decode_options(),
+                      const Allocator& alloc = Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(accept_all), 
+         eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    // Constructors that set parse error codes
+
+    template <class Sourceable>
+    basic_ubjson_cursor(Sourceable&& source, 
+                        std::error_code& ec)
+       : basic_ubjson_cursor(std::allocator_arg, Allocator(),
+                             std::forward<Sourceable>(source), 
+                             ubjson_decode_options(), 
+                             ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_ubjson_cursor(Sourceable&& source, 
+                        const ubjson_decode_options& options,
+                        std::error_code& ec)
+       : basic_ubjson_cursor(std::allocator_arg, Allocator(),
+                             std::forward<Sourceable>(source), 
+                             options, 
+                             ec)
+    {
+    }
+
+    template <class Sourceable>
+    basic_ubjson_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                        Sourceable&& source,
+                        const ubjson_decode_options& options,
+                        std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(accept_all),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    void reset()
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    void reset(std::error_code& ec)
+    {
+        parser_.reset();
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source, std::error_code& ec)
+    {
+        parser_.reset(std::forward<Sourceable>(source));
+        cursor_visitor_.reset();
+        eof_ = false;
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    bool done() const override
+    {
+        return parser_.done();
+    }
+
+    const staj_event& current() const override
+    {
+        return cursor_visitor_.event();
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor) override
+    {
+        std::error_code ec;
+        read_to(visitor, ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void read_to(basic_json_visitor<char_type>& visitor,
+                std::error_code& ec) override
+    {
+        if (staj_to_saj_event(cursor_visitor_.event(), visitor, *this, ec))
+        {
+            read_next(visitor, ec);
+        }
+    }
+
+    void next() override
+    {
+        std::error_code ec;
+        next(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column()));
+        }
+    }
+
+    void next(std::error_code& ec) override
+    {
+        read_next(ec);
+    }
+
+    const ser_context& context() const override
+    {
+        return *this;
+    }
+
+    bool eof() const
+    {
+        return eof_;
+    }
+
+    std::size_t line() const override
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const override
+    {
+        return parser_.column();
+    }
+
+    friend
+    staj_filter_view operator|(basic_ubjson_cursor& cursor, 
+                               std::function<bool(const staj_event&, const ser_context&)> pred)
+    {
+        return staj_filter_view(cursor, pred);
+    }
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_ubjson_cursor(Sourceable&& source,
+                      std::function<bool(const staj_event&, const ser_context&)> filter,
+                      const ubjson_decode_options& options = ubjson_decode_options(),
+                      const Allocator& alloc = Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc), 
+         cursor_visitor_(filter), 
+         eof_(false)
+    {
+        if (!done())
+        {
+            next();
+        }
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_ubjson_cursor(Sourceable&& source, 
+                        std::function<bool(const staj_event&, const ser_context&)> filter,
+                        std::error_code& ec)
+       : basic_ubjson_cursor(std::allocator_arg, Allocator(),
+                             std::forward<Sourceable>(source), filter, ec)
+    {
+    }
+
+    template <class Sourceable>
+    JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter")
+    basic_ubjson_cursor(std::allocator_arg_t, const Allocator& alloc, 
+                        Sourceable&& source,
+                        std::function<bool(const staj_event&, const ser_context&)> filter,
+                        std::error_code& ec)
+       : parser_(std::forward<Sourceable>(source), alloc), 
+         cursor_visitor_(filter),
+         eof_(false)
+    {
+        if (!done())
+        {
+            next(ec);
+        }
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&)")
+    void read(basic_json_visitor<char_type>& visitor)
+    {
+        read_to(visitor);
+    }
+
+    JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&, std::error_code&)")
+    void read(basic_json_visitor<char_type>& visitor,
+                 std::error_code& ec) 
+    {
+        read_to(visitor, ec);
+    }
+#endif
+private:
+    static bool accept_all(const staj_event&, const ser_context&) 
+    {
+        return true;
+    }
+
+    void read_next(std::error_code& ec)
+    {
+        parser_.restart();
+        while (!parser_.stopped())
+        {
+            parser_.parse(cursor_visitor_, ec);
+            if (ec) return;
+        }
+    }
+
+    void read_next(basic_json_visitor<char_type>& visitor, std::error_code& ec)
+    {
+        parser_.restart();
+        while (!parser_.stopped())
+        {
+            parser_.parse(visitor, ec);
+            if (ec) return;
+        }
+    }
+};
+
+using ubjson_stream_cursor = basic_ubjson_cursor<jsoncons::binary_stream_source>;
+using ubjson_bytes_cursor = basic_ubjson_cursor<jsoncons::bytes_source>;
+
+} // namespace ubjson
+} // namespace jsoncons
+
+#endif
+
diff --git a/include/jsoncons_ext/ubjson/ubjson_encoder.hpp b/include/jsoncons_ext/ubjson/ubjson_encoder.hpp
new file mode 100644
index 0000000..2d90e4a
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_encoder.hpp
@@ -0,0 +1,502 @@
+// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_ENCODER_HPP
+#define JSONCONS_UBJSON_UBJSON_ENCODER_HPP
+
+#include <string>
+#include <vector>
+#include <limits> // std::numeric_limits
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json_exception.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/sink.hpp>
+#include <jsoncons/detail/parse_number.hpp>
+#include <jsoncons_ext/ubjson/ubjson_type.hpp>
+#include <jsoncons_ext/ubjson/ubjson_error.hpp>
+#include <jsoncons_ext/ubjson/ubjson_options.hpp>
+
+namespace jsoncons { namespace ubjson {
+
+enum class ubjson_container_type {object, indefinite_length_object, array, indefinite_length_array};
+
+template<class Sink=jsoncons::binary_stream_sink,class Allocator=std::allocator<char>>
+class basic_ubjson_encoder final : public basic_json_visitor<char>
+{
+
+    enum class decimal_parse_state { start, integer, exp1, exp2, fraction1 };
+public:
+    using allocator_type = Allocator;
+    using typename basic_json_visitor<char>::string_view_type;
+    using sink_type = Sink;
+
+private:
+    struct stack_item
+    {
+        ubjson_container_type type_;
+        std::size_t length_;
+        std::size_t count_;
+
+        stack_item(ubjson_container_type type, std::size_t length = 0) noexcept
+           : type_(type), length_(length), count_(0)
+        {
+        }
+
+        std::size_t length() const
+        {
+            return length_;
+        }
+
+        std::size_t count() const
+        {
+            return count_;
+        }
+
+        bool is_object() const
+        {
+            return type_ == ubjson_container_type::object || type_ == ubjson_container_type::indefinite_length_object;
+        }
+
+        bool is_indefinite_length() const
+        {
+            return type_ == ubjson_container_type::indefinite_length_array || type_ == ubjson_container_type::indefinite_length_object;
+        }
+
+    };
+
+    Sink sink_;
+    const ubjson_encode_options options_;
+    allocator_type alloc_;
+
+    std::vector<stack_item> stack_;
+    int nesting_depth_;
+
+    // Noncopyable and nonmoveable
+    basic_ubjson_encoder(const basic_ubjson_encoder&) = delete;
+    basic_ubjson_encoder& operator=(const basic_ubjson_encoder&) = delete;
+public:
+    basic_ubjson_encoder(Sink&& sink, 
+                         const Allocator& alloc = Allocator())
+       : basic_ubjson_encoder(std::forward<Sink>(sink), ubjson_encode_options(), alloc)
+    {
+    }
+
+    explicit basic_ubjson_encoder(Sink&& sink, 
+                                  const ubjson_encode_options& options, 
+                                  const Allocator& alloc = Allocator())
+       : sink_(std::forward<Sink>(sink)),
+         options_(options),
+         alloc_(alloc),
+         nesting_depth_(0)
+    {
+    }
+
+    void reset()
+    {
+        stack_.clear();
+        nesting_depth_ = 0;
+    }
+
+    void reset(Sink&& sink)
+    {
+        sink_ = std::move(sink);
+        reset();
+    }
+
+    ~basic_ubjson_encoder() noexcept
+    {
+        JSONCONS_TRY
+        {
+            sink_.flush();
+        }
+        JSONCONS_CATCH(...)
+        {
+        }
+    }
+
+private:
+    // Implementing methods
+
+    void visit_flush() override
+    {
+        sink_.flush();
+    }
+
+    bool visit_begin_object(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = ubjson_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(ubjson_container_type::indefinite_length_object);
+        sink_.push_back(jsoncons::ubjson::ubjson_type::start_object_marker);
+
+        return true;
+    }
+
+    bool visit_begin_object(std::size_t length, semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = ubjson_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(ubjson_container_type::object, length);
+        sink_.push_back(jsoncons::ubjson::ubjson_type::start_object_marker);
+        sink_.push_back(jsoncons::ubjson::ubjson_type::count_marker);
+        put_length(length);
+
+        return true;
+    }
+
+    bool visit_end_object(const ser_context&, std::error_code& ec) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        --nesting_depth_;
+
+        if (stack_.back().is_indefinite_length())
+        {
+            sink_.push_back(jsoncons::ubjson::ubjson_type::end_object_marker);
+        }
+        else
+        {
+            if (stack_.back().count() < stack_.back().length())
+            {
+                ec = ubjson_errc::too_few_items;
+                return false;
+            }
+            if (stack_.back().count() > stack_.back().length())
+            {
+                ec = ubjson_errc::too_many_items;
+                return false;
+            }
+        }
+        stack_.pop_back();
+        end_value();
+        return true;
+    }
+
+    bool visit_begin_array(semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = ubjson_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(ubjson_container_type::indefinite_length_array);
+        sink_.push_back(jsoncons::ubjson::ubjson_type::start_array_marker);
+
+        return true;
+    }
+
+    bool visit_begin_array(std::size_t length, semantic_tag, const ser_context&, std::error_code& ec) override
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = ubjson_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
+        stack_.emplace_back(ubjson_container_type::array, length);
+        sink_.push_back(jsoncons::ubjson::ubjson_type::start_array_marker);
+        sink_.push_back(jsoncons::ubjson::ubjson_type::count_marker);
+        put_length(length);
+
+        return true;
+    }
+
+    bool visit_end_array(const ser_context&, std::error_code& ec) override
+    {
+        JSONCONS_ASSERT(!stack_.empty());
+        --nesting_depth_;
+
+        if (stack_.back().is_indefinite_length())
+        {
+            sink_.push_back(jsoncons::ubjson::ubjson_type::end_array_marker);
+        }
+        else
+        {
+            if (stack_.back().count() < stack_.back().length())
+            {
+                ec = ubjson_errc::too_few_items;
+                return false;
+            }
+            if (stack_.back().count() > stack_.back().length())
+            {
+                ec = ubjson_errc::too_many_items;
+                return false;
+            }
+        }
+        stack_.pop_back();
+        end_value();
+        return true;
+    }
+
+    bool visit_key(const string_view_type& name, const ser_context&, std::error_code& ec) override
+    {
+        auto sink = unicode_traits::validate(name.data(), name.size());
+        if (sink.ec != unicode_traits::conv_errc())
+        {
+            ec = ubjson_errc::invalid_utf8_text_string;
+            return false;
+        }
+
+        put_length(name.length());
+
+        for (auto c : name)
+        {
+            sink_.push_back(c);
+        }
+        return true;
+    }
+
+    bool visit_null(semantic_tag, const ser_context&, std::error_code&) override
+    {
+        // nil
+        binary::native_to_big(static_cast<uint8_t>(jsoncons::ubjson::ubjson_type::null_type), std::back_inserter(sink_));
+        end_value();
+        return true;
+    }
+
+    bool visit_string(const string_view_type& sv, semantic_tag tag, const ser_context&, std::error_code& ec) override
+    {
+        switch (tag)
+        {
+            case semantic_tag::bigint:
+            case semantic_tag::bigdec:
+            {
+                sink_.push_back(jsoncons::ubjson::ubjson_type::high_precision_number_type);
+                break;
+            }
+            default:
+            {
+                sink_.push_back(jsoncons::ubjson::ubjson_type::string_type);
+                break;
+            }
+        }
+
+        auto sink = unicode_traits::validate(sv.data(), sv.size());
+        if (sink.ec != unicode_traits::conv_errc())
+        {
+            ec = ubjson_errc::invalid_utf8_text_string;
+            return false;
+        }
+
+        put_length(sv.length());
+
+        for (auto c : sv)
+        {
+            sink_.push_back(c);
+        }
+
+        end_value();
+        return true;
+    }
+
+    void put_length(std::size_t length)
+    {
+        if (length <= (std::numeric_limits<uint8_t>::max)())
+        {
+            sink_.push_back(ubjson_type::uint8_type);
+            binary::native_to_big(static_cast<uint8_t>(length), std::back_inserter(sink_));
+        }
+        else if (length <= (std::size_t)(std::numeric_limits<int16_t>::max)())
+        {
+            sink_.push_back(ubjson_type::int16_type);
+            binary::native_to_big(static_cast<uint16_t>(length), std::back_inserter(sink_));
+        }
+        else if (length <= (std::size_t)(std::numeric_limits<int32_t>::max)())
+        {
+            sink_.push_back(ubjson_type::int32_type);
+            binary::native_to_big(static_cast<uint32_t>(length),std::back_inserter(sink_));
+        }
+        else if (length <= (std::size_t)(std::numeric_limits<int64_t>::max)())
+        {
+            sink_.push_back(ubjson_type::int64_type);
+            binary::native_to_big(static_cast<uint64_t>(length),std::back_inserter(sink_));
+        }
+        else
+        {
+            JSONCONS_THROW(ser_error(ubjson_errc::too_many_items));
+        }
+    }
+
+    bool visit_byte_string(const byte_string_view& b, 
+                              semantic_tag, 
+                              const ser_context&,
+                              std::error_code&) override
+    {
+
+        const size_t length = b.size();
+        sink_.push_back(jsoncons::ubjson::ubjson_type::start_array_marker);
+        binary::native_to_big(static_cast<uint8_t>(jsoncons::ubjson::ubjson_type::type_marker), std::back_inserter(sink_));
+        binary::native_to_big(static_cast<uint8_t>(jsoncons::ubjson::ubjson_type::uint8_type), std::back_inserter(sink_));
+        put_length(length);
+
+        for (auto c : b)
+        {
+            sink_.push_back(c);
+        }
+
+        end_value();
+        return true;
+    }
+
+    bool visit_double(double val, 
+                         semantic_tag,
+                         const ser_context&,
+                         std::error_code&) override
+    {
+        float valf = (float)val;
+        if ((double)valf == val)
+        {
+            // float 32
+            sink_.push_back(static_cast<uint8_t>(jsoncons::ubjson::ubjson_type::float32_type));
+            binary::native_to_big(valf,std::back_inserter(sink_));
+        }
+        else
+        {
+            // float 64
+            sink_.push_back(static_cast<uint8_t>(jsoncons::ubjson::ubjson_type::float64_type));
+            binary::native_to_big(val,std::back_inserter(sink_));
+        }
+
+        // write double
+
+        end_value();
+        return true;
+    }
+
+    bool visit_int64(int64_t val, 
+                        semantic_tag, 
+                        const ser_context&,
+                        std::error_code&) override
+    {
+        if (val >= 0)
+        {
+            if (val <= (std::numeric_limits<uint8_t>::max)())
+            {
+                // uint 8 stores a 8-bit unsigned integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::uint8_type);
+                binary::native_to_big(static_cast<uint8_t>(val),std::back_inserter(sink_));
+            }
+            else if (val <= (std::numeric_limits<int16_t>::max)())
+            {
+                // uint 16 stores a 16-bit big-endian unsigned integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int16_type);
+                binary::native_to_big(static_cast<int16_t>(val),std::back_inserter(sink_));
+            }
+            else if (val <= (std::numeric_limits<int32_t>::max)())
+            {
+                // uint 32 stores a 32-bit big-endian unsigned integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int32_type);
+                binary::native_to_big(static_cast<int32_t>(val),std::back_inserter(sink_));
+            }
+            else if (val <= (std::numeric_limits<int64_t>::max)())
+            {
+                // int 64 stores a 64-bit big-endian signed integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int64_type);
+                binary::native_to_big(static_cast<int64_t>(val),std::back_inserter(sink_));
+            }
+            else
+            {
+                // big integer
+            }
+        }
+        else
+        {
+            if (val >= (std::numeric_limits<int8_t>::lowest)())
+            {
+                // int 8 stores a 8-bit signed integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int8_type);
+                binary::native_to_big(static_cast<int8_t>(val),std::back_inserter(sink_));
+            }
+            else if (val >= (std::numeric_limits<int16_t>::lowest)())
+            {
+                // int 16 stores a 16-bit big-endian signed integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int16_type);
+                binary::native_to_big(static_cast<int16_t>(val),std::back_inserter(sink_));
+            }
+            else if (val >= (std::numeric_limits<int32_t>::lowest)())
+            {
+                // int 32 stores a 32-bit big-endian signed integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int32_type);
+                binary::native_to_big(static_cast<int32_t>(val),std::back_inserter(sink_));
+            }
+            else if (val >= (std::numeric_limits<int64_t>::lowest)())
+            {
+                // int 64 stores a 64-bit big-endian signed integer
+                sink_.push_back(jsoncons::ubjson::ubjson_type::int64_type);
+                binary::native_to_big(static_cast<int64_t>(val),std::back_inserter(sink_));
+            }
+        }
+        end_value();
+        return true;
+    }
+
+    bool visit_uint64(uint64_t val, 
+                      semantic_tag, 
+                      const ser_context&,
+                      std::error_code&) override
+    {
+        if (val <= (std::numeric_limits<uint8_t>::max)())
+        {
+            sink_.push_back(jsoncons::ubjson::ubjson_type::uint8_type);
+            binary::native_to_big(static_cast<uint8_t>(val),std::back_inserter(sink_));
+        }
+        else if (val <= static_cast<uint64_t>((std::numeric_limits<int16_t>::max)()))
+        {
+            sink_.push_back(jsoncons::ubjson::ubjson_type::int16_type);
+            binary::native_to_big(static_cast<int16_t>(val),std::back_inserter(sink_));
+        }
+        else if (val <= static_cast<uint64_t>((std::numeric_limits<int32_t>::max)()))
+        {
+            sink_.push_back(jsoncons::ubjson::ubjson_type::int32_type);
+            binary::native_to_big(static_cast<int32_t>(val),std::back_inserter(sink_));
+        }
+        else if (val <= static_cast<uint64_t>((std::numeric_limits<int64_t>::max)()))
+        {
+            sink_.push_back(jsoncons::ubjson::ubjson_type::int64_type);
+            binary::native_to_big(static_cast<int64_t>(val),std::back_inserter(sink_));
+        }
+        end_value();
+        return true;
+    }
+
+    bool visit_bool(bool val, semantic_tag, const ser_context&, std::error_code&) override
+    {
+        // true and false
+        sink_.push_back(static_cast<uint8_t>(val ? jsoncons::ubjson::ubjson_type::true_type : jsoncons::ubjson::ubjson_type::false_type));
+
+        end_value();
+        return true;
+    }
+
+    void end_value()
+    {
+        if (!stack_.empty())
+        {
+            ++stack_.back().count_;
+        }
+    }
+};
+
+using ubjson_stream_encoder = basic_ubjson_encoder<jsoncons::binary_stream_sink>;
+using ubjson_bytes_encoder = basic_ubjson_encoder<jsoncons::bytes_sink<std::vector<uint8_t>>>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+template<class Sink=jsoncons::binary_stream_sink>
+using basic_ubjson_serializer = basic_ubjson_encoder<Sink>; 
+
+JSONCONS_DEPRECATED_MSG("Instead, use ubjson_stream_encoder") typedef ubjson_stream_encoder ubjson_encoder;
+JSONCONS_DEPRECATED_MSG("Instead, use ubjson_stream_encoder") typedef ubjson_stream_encoder ubjson_serializer;
+JSONCONS_DEPRECATED_MSG("Instead, use ubjson_bytes_encoder") typedef ubjson_bytes_encoder ubjson_buffer_serializer;
+#endif
+
+}}
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson_error.hpp b/include/jsoncons_ext/ubjson/ubjson_error.hpp
new file mode 100644
index 0000000..cc7f5b8
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_error.hpp
@@ -0,0 +1,100 @@
+/// Copyright 2018 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_ERROR_HPP
+#define JSONCONS_UBJSON_UBJSON_ERROR_HPP
+
+#include <system_error>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace ubjson {
+
+enum class ubjson_errc
+{
+    success = 0,
+    unexpected_eof = 1,
+    source_error,
+    count_required_after_type,
+    length_is_negative,
+    length_must_be_integer,
+    unknown_type,
+    invalid_utf8_text_string,
+    too_many_items,
+    too_few_items,
+    number_too_large,
+    max_nesting_depth_exceeded,
+    key_expected,
+    max_items_exceeded
+};
+
+class ubjson_error_category_impl
+   : public std::error_category
+{
+public:
+    const char* name() const noexcept override
+    {
+        return "jsoncons/ubjson";
+    }
+    std::string message(int ev) const override
+    {
+        switch (static_cast<ubjson_errc>(ev))
+        {
+            case ubjson_errc::unexpected_eof:
+                return "Unexpected end of file";
+            case ubjson_errc::source_error:
+                return "Source error";
+            case ubjson_errc::count_required_after_type:
+                return "Type is specified for container, but count is not specified";
+            case ubjson_errc::length_is_negative:
+                return "Request for the length of an array, map or string returned a negative result";
+            case ubjson_errc::length_must_be_integer:
+                return "Length must be a integer numeric type (int8, uint8, int16, int32, int64)";
+            case ubjson_errc::unknown_type:
+                return "Unknown type";
+            case ubjson_errc::invalid_utf8_text_string:
+                return "Illegal UTF-8 encoding in text string";
+            case ubjson_errc::too_many_items:
+                return "Too many items were added to a UBJSON object or array of known length";
+            case ubjson_errc::too_few_items:
+                return "Too few items were added to a UBJSON object or array of known length";
+            case ubjson_errc::number_too_large:
+                return "Number exceeds implementation limits";
+            case ubjson_errc::max_nesting_depth_exceeded:
+                return "Data item nesting exceeds limit in options";
+            case ubjson_errc::key_expected:
+                return "Text string key in a map expected";
+            case ubjson_errc::max_items_exceeded:
+                return "Number of items in UBJSON object or array exceeds limit set in options";
+            default:
+                return "Unknown UBJSON parser error";
+        }
+    }
+};
+
+inline
+const std::error_category& ubjson_error_category()
+{
+  static ubjson_error_category_impl instance;
+  return instance;
+}
+
+inline 
+std::error_code make_error_code(ubjson_errc e)
+{
+    return std::error_code(static_cast<int>(e),ubjson_error_category());
+}
+
+
+}}
+
+namespace std {
+    template<>
+    struct is_error_code_enum<jsoncons::ubjson::ubjson_errc> : public true_type
+    {
+    };
+}
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson_options.hpp b/include/jsoncons_ext/ubjson/ubjson_options.hpp
new file mode 100644
index 0000000..1498d50
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_options.hpp
@@ -0,0 +1,87 @@
+// Copyright 2019 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_OPTIONS_HPP
+#define JSONCONS_UBJSON_UBJSON_OPTIONS_HPP
+
+#include <string>
+#include <limits> // std::numeric_limits
+#include <cwchar>
+#include <jsoncons/json_exception.hpp>
+
+namespace jsoncons { namespace ubjson {
+
+class ubjson_options;
+
+class ubjson_options_common
+{
+    friend class ubjson_options;
+
+    int max_nesting_depth_;
+protected:
+    virtual ~ubjson_options_common() = default;
+
+    ubjson_options_common()
+        : max_nesting_depth_(1024)
+    {
+    }
+
+    ubjson_options_common(const ubjson_options_common&) = default;
+    ubjson_options_common& operator=(const ubjson_options_common&) = default;
+    ubjson_options_common(ubjson_options_common&&) = default;
+    ubjson_options_common& operator=(ubjson_options_common&&) = default;
+public:
+    int max_nesting_depth() const 
+    {
+        return max_nesting_depth_;
+    }
+};
+
+class ubjson_decode_options : public virtual ubjson_options_common
+{
+    friend class ubjson_options;
+    std::size_t max_items_;
+public:
+    ubjson_decode_options() :
+         max_items_(1 << 24)
+    {
+    }
+
+    std::size_t max_items() const
+    {
+        return max_items_;
+    }
+};
+
+class ubjson_encode_options : public virtual ubjson_options_common
+{
+    friend class ubjson_options;
+public:
+    ubjson_encode_options()
+    {
+    }
+};
+
+class ubjson_options final : public ubjson_decode_options, public ubjson_encode_options
+{
+public:
+    using ubjson_options_common::max_nesting_depth;
+
+    ubjson_options& max_nesting_depth(int value)
+    {
+        this->max_nesting_depth_ = value;
+        return *this;
+    }
+
+    ubjson_options& max_items(std::size_t value)
+    {
+        this->max_items_ = value;
+        return *this;
+    }
+};
+
+}}
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson_parser.hpp b/include/jsoncons_ext/ubjson/ubjson_parser.hpp
new file mode 100644
index 0000000..468f139
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_parser.hpp
@@ -0,0 +1,880 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_PARSER_HPP
+#define JSONCONS_UBJSON_UBJSON_PARSER_HPP
+
+#include <string>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/ubjson/ubjson_type.hpp>
+#include <jsoncons_ext/ubjson/ubjson_error.hpp>
+#include <jsoncons_ext/ubjson/ubjson_options.hpp>
+
+namespace jsoncons { namespace ubjson {
+
+enum class parse_mode {root,accept,array,indefinite_array,strongly_typed_array,map_key,map_value,strongly_typed_map_key,strongly_typed_map_value,indefinite_map_key,indefinite_map_value};
+
+struct parse_state 
+{
+    parse_mode mode; 
+    std::size_t length;
+    uint8_t type;
+    std::size_t index;
+
+    parse_state(parse_mode mode, std::size_t length, uint8_t type = 0) noexcept
+        : mode(mode), length(length), type(type), index(0)
+    {
+    }
+
+    parse_state(const parse_state&) = default;
+    parse_state(parse_state&&) = default;
+};
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_ubjson_parser : public ser_context
+{
+    using char_type = char;
+    using char_traits_type = std::char_traits<char>;
+    using temp_allocator_type = Allocator;
+    using char_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<char_type>;                  
+    using byte_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<uint8_t>;                  
+    using parse_state_allocator_type = typename std::allocator_traits<temp_allocator_type>:: template rebind_alloc<parse_state>;                         
+
+    Source source_;
+    ubjson_decode_options options_;
+    bool more_;
+    bool done_;
+    std::basic_string<char,std::char_traits<char>,char_allocator_type> text_buffer_;
+    std::vector<parse_state,parse_state_allocator_type> state_stack_;
+    int nesting_depth_;
+public:
+    template <class Sourceable>
+        basic_ubjson_parser(Sourceable&& source,
+                          const ubjson_decode_options& options = ubjson_decode_options(),
+                          const Allocator alloc = Allocator())
+       : source_(std::forward<Sourceable>(source)), 
+         options_(options),
+         more_(true), 
+         done_(false),
+         text_buffer_(alloc),
+         state_stack_(alloc),
+         nesting_depth_(0)
+    {
+        state_stack_.emplace_back(parse_mode::root,0);
+    }
+
+    void restart()
+    {
+        more_ = true;
+    }
+
+    void reset()
+    {
+        more_ = true;
+        done_ = false;
+        text_buffer_.clear();
+        state_stack_.clear();
+        state_stack_.emplace_back(parse_mode::root,0,0);
+        nesting_depth_ = 0;
+    }
+
+    template <class Sourceable>
+    void reset(Sourceable&& source)
+    {
+        source_ = std::forward<Sourceable>(source);
+        reset();
+    }
+
+    bool done() const
+    {
+        return done_;
+    }
+
+    bool stopped() const
+    {
+        return !more_;
+    }
+
+    std::size_t line() const override
+    {
+        return 0;
+    }
+
+    std::size_t column() const override
+    {
+        return source_.position();
+    }
+
+    void parse(json_visitor& visitor, std::error_code& ec)
+    {
+        while (!done_ && more_)
+        {
+            switch (state_stack_.back().mode)
+            {
+                case parse_mode::array:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        read_type_and_value(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        end_array(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::strongly_typed_array:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        read_value(visitor, state_stack_.back().type, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        end_array(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::indefinite_array:
+                {
+                    auto c = source_.peek();
+                    if (c.eof)
+                    {
+                        ec = ubjson_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (c.value == jsoncons::ubjson::ubjson_type::end_array_marker)
+                    {
+                        source_.ignore(1);
+                        end_array(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        if (++state_stack_.back().index > options_.max_items())
+                        {
+                            ec = ubjson_errc::max_items_exceeded;
+                            more_ = false;
+                            return;
+                        }
+                        read_type_and_value(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    break;
+                }
+                case parse_mode::map_key:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        read_key(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                        state_stack_.back().mode = parse_mode::map_value;
+                    }
+                    else
+                    {
+                        end_object(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::map_value:
+                {
+                    state_stack_.back().mode = parse_mode::map_key;
+                    read_type_and_value(visitor, ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    break;
+                }
+                case parse_mode::strongly_typed_map_key:
+                {
+                    if (state_stack_.back().index < state_stack_.back().length)
+                    {
+                        ++state_stack_.back().index;
+                        read_key(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                        state_stack_.back().mode = parse_mode::strongly_typed_map_value;
+                    }
+                    else
+                    {
+                        end_object(visitor, ec);
+                    }
+                    break;
+                }
+                case parse_mode::strongly_typed_map_value:
+                {
+                    state_stack_.back().mode = parse_mode::strongly_typed_map_key;
+                    read_value(visitor, state_stack_.back().type, ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    break;
+                }
+                case parse_mode::indefinite_map_key:
+                {
+                    auto c = source_.peek();
+                    if (c.eof)
+                    {
+                        ec = ubjson_errc::unexpected_eof;
+                        more_ = false;
+                        return;
+                    }
+                    if (c.value == jsoncons::ubjson::ubjson_type::end_object_marker)
+                    {
+                        source_.ignore(1);
+                        end_object(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        if (++state_stack_.back().index > options_.max_items())
+                        {
+                            ec = ubjson_errc::max_items_exceeded;
+                            more_ = false;
+                            return;
+                        }
+                        read_key(visitor, ec);
+                        if (ec)
+                        {
+                            return;
+                        }
+                        state_stack_.back().mode = parse_mode::indefinite_map_value;
+                    }
+                    break;
+                }
+                case parse_mode::indefinite_map_value:
+                {
+                    state_stack_.back().mode = parse_mode::indefinite_map_key;
+                    read_type_and_value(visitor, ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    break;
+                }
+                case parse_mode::root:
+                {
+                    state_stack_.back().mode = parse_mode::accept;
+                    read_type_and_value(visitor, ec);
+                    if (ec)
+                    {
+                        return;
+                    }
+                    break;
+                }
+                case parse_mode::accept:
+                {
+                    JSONCONS_ASSERT(state_stack_.size() == 1);
+                    state_stack_.clear();
+                    more_ = false;
+                    done_ = true;
+                    visitor.flush();
+                    break;
+                }
+            }
+        }
+    }
+private:
+    void read_type_and_value(json_visitor& visitor, std::error_code& ec)
+    {
+        if (source_.is_error())
+        {
+            ec = ubjson_errc::source_error;
+            more_ = false;
+            return;
+        }   
+
+        uint8_t b;
+        if (source_.read(&b, 1) == 0)
+        {
+            ec = ubjson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        read_value(visitor, b, ec);
+    }
+
+    void read_value(json_visitor& visitor, uint8_t type, std::error_code& ec)
+    {
+        switch (type)
+        {
+            case jsoncons::ubjson::ubjson_type::null_type: 
+            {
+                more_ = visitor.null_value(semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::no_op_type: 
+            {
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::true_type:
+            {
+                more_ = visitor.bool_value(true, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::false_type:
+            {
+                more_ = visitor.bool_value(false, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int8_type: 
+            {
+                uint8_t buf[sizeof(int8_t)];
+                if (source_.read(buf, sizeof(int8_t)) != sizeof(int8_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                int8_t val = binary::big_to_native<int8_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::uint8_type: 
+            {
+                uint8_t b;
+                if (source_.read(&b, 1) == 0)
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.uint64_value(b, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int16_type: 
+            {
+                uint8_t buf[sizeof(int16_t)];
+                if (source_.read(buf, sizeof(int16_t)) != sizeof(int16_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                int16_t val = binary::big_to_native<int16_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int32_type: 
+            {
+                uint8_t buf[sizeof(int32_t)];
+                if (source_.read(buf, sizeof(int32_t)) != sizeof(int32_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                int32_t val = binary::big_to_native<int32_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int64_type: 
+            {
+                uint8_t buf[sizeof(int64_t)];
+                if (source_.read(buf, sizeof(int64_t)) != sizeof(int64_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                int64_t val = binary::big_to_native<int64_t>(buf, sizeof(buf));
+                more_ = visitor.int64_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::float32_type: 
+            {
+                uint8_t buf[sizeof(float)];
+                if (source_.read(buf, sizeof(float)) != sizeof(float))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                float val = binary::big_to_native<float>(buf, sizeof(buf));
+                more_ = visitor.double_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::float64_type: 
+            {
+                uint8_t buf[sizeof(double)];
+                if (source_.read(buf, sizeof(double)) != sizeof(double))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                double val = binary::big_to_native<double>(buf, sizeof(buf));
+                more_ = visitor.double_value(val, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::char_type: 
+            {
+                text_buffer_.clear();
+                if (source_reader<Source>::read(source_,text_buffer_,1) != 1)
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+                if (result.ec != unicode_traits::conv_errc())
+                {
+                    ec = ubjson_errc::invalid_utf8_text_string;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.string_value(text_buffer_, semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::string_type: 
+            {
+                std::size_t length = get_length(ec);
+                if (ec)
+                {
+                    return;
+                }
+                text_buffer_.clear();
+                if (source_reader<Source>::read(source_,text_buffer_,length) != length)
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+                if (result.ec != unicode_traits::conv_errc())
+                {
+                    ec = ubjson_errc::invalid_utf8_text_string;
+                    more_ = false;
+                    return;
+                }
+                more_ = visitor.string_value(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), semantic_tag::none, *this, ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::high_precision_number_type: 
+            {
+                std::size_t length = get_length(ec);
+                if (ec)
+                {
+                    return;
+                }
+                text_buffer_.clear();
+                if (source_reader<Source>::read(source_,text_buffer_,length) != length)
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return;
+                }
+                if (jsoncons::detail::is_base10(text_buffer_.data(),text_buffer_.length()))
+                {
+                    more_ = visitor.string_value(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), semantic_tag::bigint, *this, ec);
+                }
+                else
+                {
+                    more_ = visitor.string_value(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), semantic_tag::bigdec, *this, ec);
+                }
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::start_array_marker: 
+            {
+                begin_array(visitor,ec);
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::start_object_marker: 
+            {
+                begin_object(visitor, ec);
+                break;
+            }
+            default:
+            {
+                ec = ubjson_errc::unknown_type;
+                break;
+            }
+        }
+        if (ec)
+        {
+            more_ = false;
+        }
+    }
+
+    void begin_array(json_visitor& visitor, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = ubjson_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = ubjson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        if (c.value == jsoncons::ubjson::ubjson_type::type_marker)
+        {
+            source_.ignore(1);
+            uint8_t b;
+            if (source_.read(&b, 1) == 0)
+            {
+                ec = ubjson_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            c = source_.peek();
+            if (c.eof)
+            {
+                ec = ubjson_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            if (c.value == jsoncons::ubjson::ubjson_type::count_marker)
+            {
+                source_.ignore(1);
+                std::size_t length = get_length(ec);
+                if (ec)
+                {
+                    return;
+                }
+                if (length > options_.max_items())
+                {
+                    ec = ubjson_errc::max_items_exceeded;
+                    more_ = false;
+                    return;
+                }
+                state_stack_.emplace_back(parse_mode::strongly_typed_array,length,b);
+                more_ = visitor.begin_array(length, semantic_tag::none, *this, ec);
+            }
+            else
+            {
+                ec = ubjson_errc::count_required_after_type;
+                more_ = false;
+                return;
+            }
+        }
+        else if (c.value == jsoncons::ubjson::ubjson_type::count_marker)
+        {
+            source_.ignore(1);
+            std::size_t length = get_length(ec);
+            if (ec)
+            {
+                return;
+            }
+            if (length > options_.max_items())
+            {
+                ec = ubjson_errc::max_items_exceeded;
+                more_ = false;
+                return;
+            }
+            state_stack_.emplace_back(parse_mode::array,length);
+            more_ = visitor.begin_array(length, semantic_tag::none, *this, ec);
+        }
+        else
+        {
+            state_stack_.emplace_back(parse_mode::indefinite_array,0);
+            more_ = visitor.begin_array(semantic_tag::none, *this, ec);
+        }
+    }
+
+    void end_array(json_visitor& visitor, std::error_code& ec)
+    {
+        --nesting_depth_;
+
+        more_ = visitor.end_array(*this, ec);
+        state_stack_.pop_back();
+    }
+
+    void begin_object(json_visitor& visitor, std::error_code& ec)
+    {
+        if (JSONCONS_UNLIKELY(++nesting_depth_ > options_.max_nesting_depth()))
+        {
+            ec = ubjson_errc::max_nesting_depth_exceeded;
+            more_ = false;
+            return;
+        } 
+
+        auto c = source_.peek();
+        if (c.eof)
+        {
+            ec = ubjson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+        if (c.value == jsoncons::ubjson::ubjson_type::type_marker)
+        {
+            source_.ignore(1);
+            uint8_t b;
+            if (source_.read(&b, 1) == 0)
+            {
+                ec = ubjson_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            c = source_.peek();
+            if (c.eof)
+            {
+                ec = ubjson_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            if (c.value == jsoncons::ubjson::ubjson_type::count_marker)
+            {
+                source_.ignore(1);
+                std::size_t length = get_length(ec);
+                if (ec)
+                {
+                    return;
+                }
+                if (length > options_.max_items())
+                {
+                    ec = ubjson_errc::max_items_exceeded;
+                    more_ = false;
+                    return;
+                }
+                state_stack_.emplace_back(parse_mode::strongly_typed_map_key,length,b);
+                more_ = visitor.begin_object(length, semantic_tag::none, *this, ec);
+            }
+            else
+            {
+                ec = ubjson_errc::count_required_after_type;
+                more_ = false;
+                return;
+            }
+        }
+        else
+        {
+            c = source_.peek();
+            if (c.eof)
+            {
+                ec = ubjson_errc::unexpected_eof;
+                more_ = false;
+                return;
+            }
+            if (c.value == jsoncons::ubjson::ubjson_type::count_marker)
+            {
+                source_.ignore(1);
+                std::size_t length = get_length(ec);
+                if (ec)
+                {
+                    return;
+                }
+                if (length > options_.max_items())
+                {
+                    ec = ubjson_errc::max_items_exceeded;
+                    more_ = false;
+                    return;
+                }
+                state_stack_.emplace_back(parse_mode::map_key,length);
+                more_ = visitor.begin_object(length, semantic_tag::none, *this, ec);
+            }
+            else
+            {
+                state_stack_.emplace_back(parse_mode::indefinite_map_key,0);
+                more_ = visitor.begin_object(semantic_tag::none, *this, ec);
+            }
+        }
+    }
+
+    void end_object(json_visitor& visitor, std::error_code& ec)
+    {
+        --nesting_depth_;
+        more_ = visitor.end_object(*this, ec);
+        state_stack_.pop_back();
+    }
+
+    std::size_t get_length(std::error_code& ec)
+    {
+        std::size_t length = 0;
+        uint8_t type;
+        if (source_.read(&type, 1) == 0)
+        {
+            ec = ubjson_errc::unexpected_eof;
+            more_ = false;
+            return length;
+        }
+        switch (type)
+        {
+            case jsoncons::ubjson::ubjson_type::int8_type: 
+            {
+                uint8_t buf[sizeof(int8_t)];
+                if (source_.read(buf, sizeof(int8_t)) != sizeof(int8_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return length;
+                }
+                int8_t val = binary::big_to_native<int8_t>(buf, sizeof(buf));
+                if (val >= 0)
+                {
+                    length = val;
+                }
+                else
+                {
+                    ec = ubjson_errc::length_is_negative;
+                    more_ = false;
+                    return length;
+                }
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::uint8_type: 
+            {
+                uint8_t b;
+                if (source_.read(&b, 1) == 0)
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return length;
+                }
+                length = b;
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int16_type: 
+            {
+                uint8_t buf[sizeof(int16_t)];
+                if (source_.read(buf, sizeof(int16_t)) != sizeof(int16_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return length;
+                }
+                int16_t val = binary::big_to_native<int16_t>(buf, sizeof(buf));
+                if (val >= 0)
+                {
+                    length = val;
+                }
+                else
+                {
+                    ec = ubjson_errc::length_is_negative;
+                    more_ = false;
+                    return length;
+                }
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int32_type: 
+            {
+                uint8_t buf[sizeof(int32_t)];
+                if (source_.read(buf, sizeof(int32_t)) != sizeof(int32_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return length;
+                }
+                int32_t val = binary::big_to_native<int32_t>(buf, sizeof(buf));
+                if (val >= 0)
+                {
+                    length = static_cast<std::size_t>(val);
+                }
+                else
+                {
+                    ec = ubjson_errc::length_is_negative;
+                    more_ = false;
+                    return length;
+                }
+                break;
+            }
+            case jsoncons::ubjson::ubjson_type::int64_type: 
+            {
+                uint8_t buf[sizeof(int64_t)];
+                if (source_.read(buf, sizeof(int64_t)) != sizeof(int64_t))
+                {
+                    ec = ubjson_errc::unexpected_eof;
+                    more_ = false;
+                    return length;
+                }
+                int64_t val = binary::big_to_native<int64_t>(buf, sizeof(buf));
+                if (val >= 0)
+                {
+                    length = (std::size_t)val;
+                    if (length != (uint64_t)val)
+                    {
+                        ec = ubjson_errc::number_too_large;
+                        more_ = false;
+                        return length;
+                    }
+                }
+                else
+                {
+                    ec = ubjson_errc::length_is_negative;
+                    more_ = false;
+                    return length;
+                }
+                break;
+            }
+            default:
+            {
+                ec = ubjson_errc::length_must_be_integer;
+                more_ = false;
+                return length;
+            }
+        }
+        return length;
+    }
+
+    void read_key(json_visitor& visitor, std::error_code& ec)
+    {
+        std::size_t length = get_length(ec);
+        if (ec)
+        {
+            ec = ubjson_errc::key_expected;
+            more_ = false;
+            return;
+        }
+        text_buffer_.clear();
+        if (source_reader<Source>::read(source_,text_buffer_,length) != length)
+        {
+            ec = ubjson_errc::unexpected_eof;
+            more_ = false;
+            return;
+        }
+
+        auto result = unicode_traits::validate(text_buffer_.data(),text_buffer_.size());
+        if (result.ec != unicode_traits::conv_errc())
+        {
+            ec = ubjson_errc::invalid_utf8_text_string;
+            more_ = false;
+            return;
+        }
+        more_ = visitor.key(jsoncons::basic_string_view<char>(text_buffer_.data(),text_buffer_.length()), *this, ec);
+    }
+};
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson_reader.hpp b/include/jsoncons_ext/ubjson/ubjson_reader.hpp
new file mode 100644
index 0000000..210403a
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_reader.hpp
@@ -0,0 +1,92 @@
+// Copyright 2017 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_READER_HPP
+#define JSONCONS_UBJSON_UBJSON_READER_HPP
+
+#include <string>
+#include <memory>
+#include <utility> // std::move
+#include <jsoncons/json.hpp>
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_visitor.hpp>
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons_ext/ubjson/ubjson_type.hpp>
+#include <jsoncons_ext/ubjson/ubjson_error.hpp>
+#include <jsoncons_ext/ubjson/ubjson_parser.hpp>
+
+namespace jsoncons { namespace ubjson {
+
+template <class Source,class Allocator=std::allocator<char>>
+class basic_ubjson_reader
+{
+    basic_ubjson_parser<Source,Allocator> parser_;
+    json_visitor& visitor_;
+public:
+    template <class Sourceable>
+    basic_ubjson_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const Allocator alloc)
+       : basic_ubjson_reader(std::forward<Sourceable>(source),
+                           visitor,
+                           ubjson_decode_options(),
+                           alloc)
+    {
+    }
+
+    template <class Sourceable>
+    basic_ubjson_reader(Sourceable&& source, 
+                      json_visitor& visitor, 
+                      const ubjson_decode_options& options = ubjson_decode_options(),
+                      const Allocator alloc=Allocator())
+       : parser_(std::forward<Sourceable>(source), options, alloc),
+         visitor_(visitor)
+    {
+    }
+
+    void read()
+    {
+        std::error_code ec;
+        read(ec);
+        if (ec)
+        {
+            JSONCONS_THROW(ser_error(ec,line(),column()));
+        }
+    }
+
+    void read(std::error_code& ec)
+    {
+        parser_.reset();
+        parser_.parse(visitor_, ec);
+        if (ec)
+        {
+            return;
+        }
+    }
+
+    std::size_t line() const 
+    {
+        return parser_.line();
+    }
+
+    std::size_t column() const
+    {
+        return parser_.column();
+    }
+};
+
+using ubjson_stream_reader = basic_ubjson_reader<jsoncons::binary_stream_source>;
+
+using ubjson_bytes_reader = basic_ubjson_reader<jsoncons::bytes_source>;
+
+#if !defined(JSONCONS_NO_DEPRECATED)
+JSONCONS_DEPRECATED_MSG("Instead, use ubjson_stream_reader") typedef ubjson_stream_reader ubjson_reader;
+JSONCONS_DEPRECATED_MSG("Instead, use ubjson_bytes_reader") typedef ubjson_bytes_reader ubjson_buffer_reader;
+#endif
+
+}}
+
+#endif
diff --git a/include/jsoncons_ext/ubjson/ubjson_type.hpp b/include/jsoncons_ext/ubjson/ubjson_type.hpp
new file mode 100644
index 0000000..ef219ce
--- /dev/null
+++ b/include/jsoncons_ext/ubjson/ubjson_type.hpp
@@ -0,0 +1,43 @@
+// Copyright 2013 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_UBJSON_UBJSON_TYPE_HPP
+#define JSONCONS_UBJSON_UBJSON_TYPE_HPP
+
+#include <string>
+#include <memory>
+#include <jsoncons/config/jsoncons_config.hpp>
+
+namespace jsoncons { namespace ubjson { 
+
+    namespace ubjson_type
+    {
+        const uint8_t null_type = 'Z';
+        const uint8_t no_op_type = 'N';
+        const uint8_t true_type = 'T';
+        const uint8_t false_type = 'F';
+        const uint8_t int8_type = 'i';
+        const uint8_t uint8_type = 'U';
+        const uint8_t int16_type = 'I';
+        const uint8_t int32_type = 'l';
+        const uint8_t int64_type = 'L';
+        const uint8_t float32_type = 'd';
+        const uint8_t float64_type = 'D';
+        const uint8_t high_precision_number_type = 'H';
+        const uint8_t char_type = 'C';
+        const uint8_t string_type = 'S';
+        const uint8_t start_array_marker = '[';
+        const uint8_t end_array_marker = ']';
+        const uint8_t start_object_marker = '{';
+        const uint8_t end_object_marker = '}';
+        const uint8_t type_marker = '$';
+        const uint8_t count_marker = '#';
+    }
+ 
+} // namespace ubjson
+} // namespace jsoncons
+
+#endif